- Zope - Zope lists

RE: [Zope] zope operations atomic?
by Clark OBrien 01 Nov '01

01 Nov '01

Here is the example I was thinking about. 1) Suppose an online store is selling product X and at a given moment its inventory is n. Two shoppers hit the buy button at about the same time. Then either: a) No conflict is detected because both threads set the inventory value to the same value, n-1. This would cause a problem if n = 1 Or: b) A conflict is detected when the last thread writes because the inventory is not n as it was when he read it. request is resubmitted but again another thread has changed made the value dirty- thread starves. -----Original Message----- From: Chris McDonough [mailto:chrism@zope.com] Sent: Thursday, November 01, 2001 6:50 AM To: Clark OBrien; k_vertigo(a)yahoo.com; zope(a)zope.org Subject: Re: [Zope] zope operations atomic? What is "the dirty read problem"? ----- Original Message ----- From: "Clark OBrien" <COBrien(a)isis-server.vuse.vanderbilt.edu> To: "'Chris McDonough'" <chrism(a)zope.com>; "Clark OBrien" <COBrien(a)isis-server.vuse.vanderbilt.edu>; <k_vertigo(a)yahoo.com>; <zope(a)zope.org> Sent: Thursday, November 01, 2001 9:39 AM Subject: RE: [Zope] zope operations atomic? > Chris, > Thanks for the explanation. I don't see how > ApplicationLevelConflictResolution > can handle the dirty read problem though. > > > > > > > -----Original Message----- > From: Chris McDonough [mailto:chrism@zope.com] > Sent: Wednesday, October 31, 2001 3:11 PM > To: Clark OBrien; k_vertigo(a)yahoo.com; zope(a)zope.org > Subject: Re: [Zope] zope operations atomic? > > > > Example: > > To count the number of files uploaded to my site I set an > > index as an attribute to a Folder. These are large files so they > > take some time to upload. What happens after two people upload at > once > > does my index only get rolled back or do the files uploaded also > > get rolled back? > > If the uploads finish at the same time (meaning the transactions will > likely commit at the same time), a ConflictError is raised, and one of > the requests is retried. > > (Note that the file needn't be uploaded from the remote browser again; > Zope keeps the request around -- which includes the cgi data, which > includes your file's data -- to retry with.) > > The uploader never notices any of this, except perhaps the site will > become sluggish. > > None of this has anything to do with the counter in your example, > except that a ConflictError is more likely to be raised when changing > "hotspot" items like a counter. > > The example you provide of a counter is one that is problematic for > ZODB for two reasons: > > 1. Multiple simultaneous commits which include counter incrementing > can cause conflicts > > 2. The undoability of FileStorage causes the Data.fs file to grow on > every successful transaction. > > These problems are orthogonal to each other; they are not related to > each other in any way except that they both occur in the default Zope > configuration. The first is solved via application level conflict > resolution > (http://www.zope.org/Members/jim/ZODB/ApplicationLevelConflictResoluti > on) as well as a storage which supports it, the second is solved by > using a nonundoing storage. > > So in the example you gave, you're most worried about problem #1, > conflicts. To solve this particular problem, you would implement a > "smart" counter that did not make itself a hotspot. There is actually > already one of these that ships with Zope. It's in the BTrees.Length > module, and it's a counter that does app-level conflict resolution. > It's also a good module to take a look at if you're interested in > seeing how conflict resolution works. > > Note that none of this is terribly different AFAICT than how most > relational databases implement multithreadedness save for the fact > that ZODB uses optimistic concurrency instead of pessimistic, allowing > the app developer to be able to handle conflict scenarios in order to > maximize performance. > > HTH, > > - C > >

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RE: [Zope] Packing the database
by Jens Hauser 01 Nov '01

01 Nov '01

Hi Steve, I don't think so ... ######CUT /dev/sda2 1.8G 744M 1.0G 42% / /dev/sda5 2.3G 65M 2.2G 3% /var /dev/sda1 37M 3.4M 31M 10% /boot /dev/sdb5 8.5G 549M 7.9G 7% /htdocs ######CUT ... and: no, it's not located on the /boot device ;-) I thought of a "owner" problem, but everything else just runs smooth. Database (data.fs) has only a size of 23MB. It's located on a Suse Linux Server. Do you have any more ideas? Best regards, Jens On Thu, 1 Nov 2001 10:09:45 -0600, Steve Drees wrote: >You are out of diskspace. > >> -----Original Message----- >> From: zope-admin(a)zope.org [mailto:zope-admin@zope.org]On Behalf Of Jens >> Hauser >> Sent: Thursday, November 01, 2001 7:49 AM >> To: zope(a)zope.org >> Subject: [Zope] Packing the database >> >> >> Hi, >> >> I looked for this issue within several mailing list archives >> before but found >> only questions - no answers.... :-( >> >> If I'm trying to pack the database with value "0" or value "7" or >> whatever, I >> get the following error message (database isn't packed): >> >> ############CUT >> Zope Error >> >> Zope has encountered an error while publishing this resource. >> >> Error Type: IOError >> Error Value: [Errno 5] Input/output error >> >> >> >> Troubleshooting Suggestions >> >> The URL may be incorrect. >> The parameters passed to this resource may be >> incorrect. >> A resource that this resource relies on may be >> encountering >> an error. >> >> For more detailed information about the error, >> please refer to >> the HTML source for this page. >> >> If the error persists please contact the site >> maintainer. Thank >> you for your patience. >> >> >> >> >> Traceback (innermost last): >> File /opt/zope/lib/python/ZPublisher/Publish.py, line 223, in >> publish_module >> File /opt/zope/lib/python/ZPublisher/Publish.py, line 187, in publish >> File /opt/zope/lib/python/Zope/__init__.py, line 226, in >> zpublisher_exception_hook >> (Object: Fake) >> File /opt/zope/lib/python/ZPublisher/Publish.py, line 171, in publish >> File /opt/zope/lib/python/ZPublisher/mapply.py, line 160, in mapply >> (Object: manage_pack) >> File /opt/zope/lib/python/ZPublisher/Publish.py, line 112, in >> call_object >> (Object: manage_pack) >> File /opt/zope/lib/python/App/ApplicationManager.py, line 419, in >> manage_pack >> (Object: LockableItem) >> File /opt/zope/lib/python/ZODB/DB.py, line 537, in pack >> File /opt/zope/lib/python/zLOG.py, line 213, in LOG >> File /opt/zope/lib/python/ZLogger/ZLogger.py, line 17, in log_write >> File /opt/zope/lib/python/ZLogger/stupidFileLogger.py, line 99, >> in __call__ >> File /opt/zope/lib/python/ZLogger/stupidFileLogger.py, line 151, in >> stupid_log_write >> IOError: (see above) >> ############CUT >> >> Any ideas? >> >> Kind regards, >> Jens Hauser >> >> j.a.m. GmbH >> Computer, Systemberatung, Webhosting, Softwareentwicklung >> Eschersheimer Landstraße 471 >> 60431 Frankfurt am Main >> fon (069) 46 09 88 - 13 >> fax (069) 46 09 88 - 78 >> url http://www.jam-gmbh.de >> >> Haben Sie schon Jamail probiert? Den eMailer für personalisierte >> Serien-Mails? Jetzt testen: http://www.jamail.de >> Already tried Jamail? Visit the personalized massmailer @ >http://www.jamail.de/us/ > >----------------------- >Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte >Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail >irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und >vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte >Weitergabe dieser Mail ist nicht gestattet. > > > >_______________________________________________ >Zope maillist - Zope(a)zope.org >http://lists.zope.org/mailman/listinfo/zope >** No cross posts or HTML encoding! ** >(Related lists - > http://lists.zope.org/mailman/listinfo/zope-announce > http://lists.zope.org/mailman/listinfo/zope-dev ) > j.a.m. GmbH Computer, Systemberatung, Webhosting, Softwareentwicklung Eschersheimer Landstraße 471 60431 Frankfurt am Main fon (069) 46 09 88 - 13 fax (069) 46 09 88 - 78 url http://www.jam-gmbh.de Haben Sie schon Jamail probiert? Den eMailer für personalisierte Serien-Mails? Jetzt testen: http://www.jamail.de Already tried Jamail? Visit the personalized massmailer @ http://www.jamail.de/us/ ----------------------- Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet.

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adding images (was: Help)
by Dieter Maurer 01 Nov '01

01 Nov '01

Scott Kuei writes: > Do you know how to use the addImage function in Image.py of CMFDefault? The > only thing I can use right now is the manage_addImage function, but it doesn't > take enough arguments which I need more. And the addImage function came with > the CMF is more appropriate for what I am doing right now. But I don't know how > to use it, any suggestions? Thank you. Several, unfortunately not very relevant for your problem. But for general use.... 1. Instead of sending your questions to me, it is much better to send them to the relevant mailing list. This way, others have a chance to help you, too. My answer goes also to "zope(a)zope.org", also your question might have been better targeted at "zope-cmf(a)zope.org". 2. I do not know the CMFDefault "addImage" function. Of course, I could change this by looking at its code, but I am a bit lazy... Here, I have just my standard answer. It probably is used somewhere in CMFDefault. Find those places and use them as examples for your task. Almost surely, you can only use the "addImage" function inside the CMF environment. You should know that... 3. You are not satisfied with "manage_addImage" because you would like to pass it additional parameters. Now, it has enough arguements to create a standard image. If you want to add more meta data, you can later (but still in the action that creates the image) add properties and give them values. Zope provides ZClasses to make such things configurable (--> Zope book)... They allow to give it also new interesting behavior... Dieter

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RE: [Zope] Any way to know if in ZMI?
by Meilicke, Scott 01 Nov '01

01 Nov '01

There are general javascript methods that let you know if you are inside a frame. Perhaps you can try one of those and do some detection about the server, or go off of the URL tail - 'manage'. Search on www.javascript.com Scott -----Original Message----- From: Sidnei da Silva [mailto:sidnei@x3ng.com.br] Sent: Thursday, November 01, 2001 9:58 AM To: zope(a)zope.org Subject: [Zope] Any way to know if in ZMI? There is any way or property that I can test to know if im inside the ZMI or not? Thanx. -- Sidnei da Silva X3ng Consultoria e Desenvolvimento Ltda. sidnei(a)x3ng.com.br _______________________________________________ Zope maillist - Zope(a)zope.org http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )

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Re: [Zope] Zope-WebDAV
by mbagepll＠memphis.edu 01 Nov '01

01 Nov '01

I have sent the output of the logger in my previous mail, as you wanted me to send. I have not received any suggestion after that. Please let me know what is wrong with the Zope-WebDAV. Hope to receive an immediate reply. --Madhavi

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Re: replicating stand-alone applications
by Paul Winkler 01 Nov '01

01 Nov '01

Jerry, I'm CC'ing the mailing list. I'm not a rocket-scientist expert on this stuff, maybe somebody else could help with things I miss. On Thu, Nov 01, 2001 at 04:32:51PM -0000, 1jerry(a)usd1.com wrote: > The current Ap loads the pickle file (which has class instances in > it), loads an additional scripting file, loads an input file (usually > .txt), then does all the processing using MetaKit. Once I created > the Product, would all I need to do is change the load (from cPickle > to reading from ZODB) to get the whole process to run from an > External Method? Yes, or from a DTML page, or Script (Python)... To get started with product programming, the Boring and Minimal products are useful. > I would like the option of running (for testing) > from within Zope, updating a local MetaKit file on the server. > > detours: I attempted to create an External Method to read the pickled > data and make it available in a namespace in Zope, just trying to > print from my ap corrupted the data.fs file: > def load(): > import myapplication > myinstance = myapplication.load('test.pkl') > print myinstance # prints facts about itself > Clicking on 'test' for this External Method produced various results That should work. You should see the printed output on the console where you started Zope. If you want to see it in your browser, replace the last line with something like: return str(myinstance) > - namely, unable to import modules within myapplication What error did you get? Does the user that runs Zope have these modules on PYTHONPATH? If not, edit your Zope start script to add to the PYTHONPATH. The following works for me: 1) Create a module on my PYTHONPATH: # foo.py class Foo: def __init__(self, data): self.data = data def __repr__(self): return repr(self.data) def __str__(self): return str(self.data) 2) Create a file in my Zope installation's Extensions directory: #foo_extmeth.py import foo def load_foo(): f = foo.Foo('hello, world!') return str(f) 3) In the Zope management interface, add an External Method: id: load_foo Title: Test the Foo class. Module Name: foo_extmeth Function Name: load_foo 4) Save the External Method, then click on the Test tab. My browser now shows: hello, world! 5) Changes to your external method will be reflected immediately in a running Zope. However, changes to your imported classes do NOT show up unless you restart zope *OR* add a reload(foo) statement to your external method AND click on "Save Changes" in the ZMI for the external method. It seems the reload isn't triggered until you do "Save Changes", I don't know why. > and after > much experimenting, it overwrote some of my folder icons (never did > run). I have no idea how you did that. {:-/ > I found little (and conflicting) documentation on External > Methods. Will creating a Product work without using External Methods? Yes. The two are completely independent. I get the feeling you're not clear on the various ways to write python code for Zope. There are four ways: 1) Simple expressions embedded in DTML or ZPT. Obviously this is very limited. 2) Python Script (aka Script (Python)). THese are objects that live in the ZODB and provide a single method or function each. Due to security concerns, there are strict limitations on what modules you can use in a Python Script. 3) External Method. A file on the filesystem, usually in your Extensions directory under the zope installation, can contain one or more functions, each of which can be loaded into zope as an External Method. These are used just like Python Scripts without the restrictions on importing. But objects created by an External Method are not automatically persistent - new instances will be created at each call, and if Zope should happen to restart in the middle of a session, the user will have to start over. 4) Product. This provides a way to extend Zope with persistent objects that can be added from the Zope management interface and define management methods for instances (e.g. instantiate, modify, delete). There are no restrictions on python code you can write in a Product. A Product's code can contain calls to other Zope objects written as DTML, External Methods, Python Scripts, anything it needs. THese are all just objects in Zope, and the calling object shouldn't need to know what kind of method it's calling. The only restrictions are the same as for any Zope object: the caller must be able to find the callee (via acquisition if necessary), and the zope user must have appropriate permissions. If you don't need your instances to be persistent, then you don't really need a Product and should be able to do everything with External Methods. > detour 2: tried XML-RPC to access Zope from Python, using xmlrpclib > with and without BasicAuthTransport mod. Creating the connection > was no problem. Every time I attempted to access anything, (lists, > page source) it returned a string with HTML code for HTML, HEAD, etc > as an invalid exception string. Does XML-RPC work with 2.4.1? What > could be wrong? Sorry, I've never tried XML-RPC. This is a question for the zope list. -- paul winkler home: http://www.slinkp.com music: http://www.reacharms.com calendars: http://www.calendargalaxy.com

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CoreSession Urgent !!!
by michael kobald 01 Nov '01

01 Nov '01

Hi, i am have a big Problem with CoreSession 0.9 (Zope 2.3.3 Win2000 Server). I have 2 Session Data Mangers (dieter and session_mgr). I i want call the getSessionData() of them both method in 1 Transaction. Via calling foo3 I get the error msgs below. I need to call both Data Mangers in 1 Transaction ! By the way: Zope 2.4.2 hangs for the rest of his live after the 2. calling of foo3 Please Help michael Code: def a(self): """khjkjh""" data = self.dieter.getSessionData() data.set('dfd', 'dsd') return None def b(self): """hjhjh""" data2 = self.session_mgr.getSessionData() return None def foo3(self, REQUEST): """hhjh""" #return "dgffdg" c = self.a() #get_transaction().commit(1) d= self.b() #data = self.session_mgr.getSessionData() return "huhuh" First Call Error Type: error Error Value: release unlocked lock Traceback (innermost last): File E:\Beehive\TeDeLine\lib\python\ZPublisher\Publish.py, line 223, in publish_module File E:\Beehive\TeDeLine\lib\python\ZPublisher\Publish.py, line 187, in publish File E:\Beehive\TeDeLine\lib\python\Zope\__init__.py, line 221, in zpublisher_exception_hook (Object: Traversable) File E:\Beehive\TeDeLine\lib\python\ZPublisher\Publish.py, line 175, in publish File E:\Beehive\TeDeLine\lib\python\Zope\__init__.py, line 235, in commit File E:\Beehive\TeDeLine\lib\python\ZODB\Transaction.py, line 335, in commit File E:\Beehive\TeDeLine\lib\python\ZODB\Connection.py, line 657, in tpc_finish File E:\Beehive\TeDeLine\lib\python\ZODB\BaseStorage.py, line 219, in tpc_finish (Object: SessionStorage) error: (see above) Second Call: Error Type: TransactionErrorError Value: A serious error, which was probably a system error, occurred in a previous database transaction. This application may be in an invalid state and must be restarted before database updates can be allowed. Beware though that if the error was due to a serious system problem, such as a disk full condition, then the application may not come up until you deal with the system problem. See your application log for information on the error that lead to this problem.

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Re: ZopeTime Error
by Dave Lehman 01 Nov '01

01 Nov '01

--- In zope@y..., Mike Doanh Tran <mtran@s...> wrote: > I tried your suggestions. I gave my defined user the same permission setting > in the security tab as the Manager Role( basically everything). But i still > get the same error. The ZopeTime() method is a call to the python DateTime > Object, it does not relate to my installed Product. > > I am running Zope 2.4.1 on Redhat 7.1 with Python 2.1.1 using Apache rewrite > engine rule . I added a "User Defined Role" in the security tab. Could it > be that my Defined User does not have the permission to call the python's > ZopeTime().Date()? Does the linux permission on /usr/local/zope/lib/python > have to set to a certain RWE by the webserver? Does anyone knows? > Thanks for any suggesstions. I'm having a very similiar problem with ZopeTime errors. I gave me "Member" role all the rights I could find, but it still doesn't work. However, if I assign that user "Manager" access explicitly, then it doesn't complain about "ZopeTime". I'm running Zope 2.4.0 under Linux and using Apache rewrite. My ISP setup Zope initially, so i'm assuming (yeah, yeah, "ass of of you and me") that he setup the permissions properly. Did you figure out anything on how to solve this? I know that if I use the "proxy" tab in Zope to assign Manager access to all my methods, it seems to work, but this is an ugly workaround, not a real solution to the problem at hand. Any advice or ideas you have would be much appreciated. --dave

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RE: [Zope] RE: "ZopeTime" not defined error?
by Dave Lehman 01 Nov '01

01 Nov '01

Thanks for the advice. I hadn't thought of doing this, and it definately works around the problem. My bigger problem and concern is that i'm suddenly getting several of these "ZopeTime" errors, and i'm not sure where they are stemming from. I have developed lots of methods using "portal_catalog.searchResults" which all seem to fail (in you're not a Manager) with this same "ZopeTime" error. Do I have to proxy *all* of the methods as Manager access? This doesn't seem right to me-- is there some other security setting in Zope/CMF that I don't know about, or have not set correctly? So now I understand how to work around this issue-- assign Manager proxy rights to all my methods. But this is treating the symptom, and not the root problem. What I still want to know is this: where does the "ZopeTime" error stem from? Why is Manager-level access required to access the ZopeTime variable? I haven't been able to find specific mention of this requirement anywhere, which still makes me think i'm doing something instrinsically wrong in either my Zope or CMF configuration/implementation. --dave On 11/01/2001 07:50:38 AM Jeffrey Robinsonwrote: >Instead of assigning users the "Manager" rights to your method that calls >ZopeTime (via the proxy tab). > >You can read more about proxies in the documentation on the zope.org site. > >Jeff > >> -----Original Message----- >> From: Dave Lehman [SMTP:davelehman@loewen.com] >> Sent: Wednesday, October 31, 2001 4:21 PM >> To: zope(a)zope.org >> Subject: [Zope] RE: "ZopeTime" not defined error? >> >> Alright, I figured out that if I assign a user "Manager" rights, then my >> custom "login_form" works. However, it does *not* work if I go to my root >> Portal folder security tab and assign all rights to the "Member" role. >> >> So does the "manager" role have other instrinsic rights? Obviously I can't >> give everyone manager rights, just to work around this issue. >> >> If I stick the "login_form" in my "custom" skin folder, where would it be >> trying to access "ZopeTime" from that is different than the "generic" >> folder? And why does it think ZopeTime is not defined? >> >> --dave >> >> >> >> _______________________________________________ >> Zope maillist - Zope(a)zope.org >> http://lists.zope.org/mailman/listinfo/zope >> ** No cross posts or HTML encoding! ** >> (Related lists - >> http://lists.zope.org/mailman/listinfo/zope-announce >> http://lists.zope.org/mailman/listinfo/zope-dev )

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Why do 95% of internet business fail & only 5% succeed
by Shaun 01 Nov '01

01 Nov '01

Dear Entrepreneur: Can you honestly say that you're earning the type of income you thought you would when you first began your networking career? Unfortunately, the history of networking says that there's a 95% chance you are not earning what you would like to earn. How many different opportunities have you been involved with? How many times have you thought, "This is the one"? If you are one of the 5% of networkers who is earning a good income, what about your team? How many of them are successful? Regretfully, you know the answer to that question as well as we do....VERY FEW! Does it bother you to know that as many as 95% of the people in your group won't even recover what they have paid to get involved? It DOES NOTT MAKE SENSE, DOES IT? How can so many people who have been successful in other walks of life, fail so miserably in networking? The Answer: Network marketing for the most part, is based on the theory of "Internal Consumption." That is, the VAST majority of the company's products are purchased and consumed by distributors, NOT real customers! Let me ask you: How many supermarkets, department stores, car dealerships, etc., do you think would survive if they depended PRIMARILY on purchases by their employees of the company's products to keep them in business? As the same rule applies in the real world of business ... It is the same with networking and home-based business. A 95% failure rate makes this clear. Even networking companies that are truely product and consumer driven find many of their distributors failing. Why? Because people simply DO NOT LIKE TO SELL! Unfortunately, for 90% or more of the distributors in any typical network marketing company, it DOESN'T MATTER how great their products are supposed to be, or how fantastic the comp plan is, or how strong the company and management team are... The VAST MAJORITY of distributors WILL STILL FAIL because people simply DO NOT LIKE TO SELL!! You nor I will EVER change that part of human nature for the masses. Is there an answer? Yes, there is, but you won't find it in any Network Marketing training manual. Unfortunately, most company owners and their top leaders already know that the vast majority won't be successful. Yet, we continue to see company after company spring up with more rhetoric, promises, etc. Why? Because the ONLY people who are guaranteed to earn any significant income if the company lasts, are the owners and their top people. Sorry, but the truth is the truth! Forget the rhetoric we're now hearing about selling online because, once again, in the year 2000, more than 90% of all online businesses DIDN'T MAKE A PROFIT! The sad part is, if we continue to do the same things over and over again that have only produced failure in the past, the result will always be the same: MORE FAILURE. While a quality product, good compensation, a strong management team, and a financially sound company are all important to the success of any company, none of these factors can replace the single most important feature that a networking company MUST HAVE ... The average person must have a chance of finding LONGTERM success. Does this mean that networking is bad? Not at all. What it does mean is that the way networking has been historically promoted for years with the emphasis on "internal product consumption" (where the distributors purchase the vast majority of products for personsal use) will continue to produce a 95% failure rate. We have a solution that works for anyone who is willing to work steadily, is consistent, and can read and follow a very simple system that was designed for beginners. This system has proven successful every time over the years for those who followed it. If you would like to experience results in your life, email us at < sean_stamm(a)yahoo.com > with "Information request" in the subject. Please include your name, country, and phone number so that we can send you the correct information. We will email you an introduction about our company and our entire system at no cost to you. We will not email you ridiculous promises, or UNPROVEN OR FAILED THEORIES...Just the facts! While no one can or should ever guarantee your success in any business, here's one thing we do promise you: The TRUTH and a system that will show you HOW TO DO THINGS STEP-BY-STEP!

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