Good afternoon all, I would like to use the VarImage product as part of a "notice board" project. Different ways data is access demand different sizes for the graphics, and the VarImage product seems to be the right tool for the task...almost. These will be graphics uploaded by the end user via a form, and I've encountered two problems where it seems VarImage ate my Zope server, presumably due to "bad input". 1) A huge JPG (~10MB) was uploaded. The server then died. 2) A bitmap was uploaded instead of a jpg/gif. The server then died. Both scenarios are repeatable, but by no means are my diagnosis skills sophisticated to comment any further on what's going on. So as a preamble to my actual question I'd welcome advice on how to more properly figure out whats going on here. It seems that processing threads are getting sent off into the wild blue yonder and never ever coming back. I figure the only way I can use VarImage for my needs is if I make sure that files are <500k and if they are actually gifs of jpegs. So my *actual* question is: How can I tell if an uploaded file is a gif or a jpg? I know I'll probably need to look at the first 4 bytes for some kind of code, but I don't know what that is (nor exactly how to do it) and am dead certain that someone out there has done this already. Thanks --- Edward J. Pollard University of Lethbridge Web Development