I-worm/Klez and a GIF query/question

Hey all, Whooooah, talk about getting a response, I posted the I-Worm/Klez question hoping to get one or two replies of people who actually got infected......I got more than 40 replies! I got two more today, but one poor dude says he got around 149 and counting! Anyway, thanks for your replies guys/girls and for the URLs, but 'nuff about virus's back to PHP.... I got a client who want a simple registeration form (Which i can do without any problem...easy.) but he wants one extra bit: at the end of the form he wants a "key" gif...(A gif with a number) that is automatically generated and that number has to be entered into the text box....the idea is that it prevents automaited registerations..... Yahoo and a couple of other big sites/portals use it. For those of you who dont know what i am talking about and are curious to see an example, try registering for an account at yahoo mail or chat or something. I understand that the new version of PHP/GD or whatever does not support GIF and i also know for PNG or JPEG i can use LIBJPEG and LIBPNG (both are installed on my webhost) but how do i do it in GIF? (He insists on GIF- the clients a &##@ his money helps pay the bills) Any ideas? and if any of you guys done anything similar, can give me the function/s or any help? ANY help appreciated and guys.....please dont send me anything more about I-Worm/Klez...I apoligise about that. All feedback appreciated even ones that just want to flame me. :-) Cheers, -Ryan. /* If you see a cop beating me, put down the @$#@ing camera and come help me! */