I think I know how to manage transactions in Zope, but I don't know how to lock Zope resources for multiple requests. For example : I have a DTML Method, called "transac1", which looks like this : <dtml-if "var==0"> <dtml-call wait_10_seconds> "waiting 10 seconds..." <dtml-call "manage_editProperties({'var':1})"> </dtml-if> wait_10_seconds is an External Method that sleeps for 10 seconds. In the other hand, I have another method, called "transac2" : <dtml-if "var==0"> <dtml-call "manage_editProperties({'var':2})"> <dtml-else> <dtml-call "manage_editProperties({'var':3})"> </dtml-if> In the parent Folder, there's a property called "var" which I use in these methods. It has an initial value of 0. The point is : if I call the first method, and while it's sleeping, I call the second one (from another window, for example), it doesn't work properly. The first one crashes, and doesn't finish right. The final "var" value is 2. I want to know if there is any way to lock the folder, and its properties, so no one can access to it until my method "transac1" finishes, and where can I find information about locking resources in Zope.