php3 php4 integration

I'm testing some php scripts (that mostly comprise of forms) on a server running php 3.0.15. I am unsure if its installed as a module or cgi interpreter (how can I check?). However, the machine it will run on has php4 installed. In terms of integration, is there anything that I need to change like the filename extensions or whatever to make it run the same as it does on the test server? I am unsure of anything on the server it is going to run on. I think the filename extensions are different for both versions. If anybody can tell me or direct me somewhere, it would be greatly appreciated. Thanks. __________________________________________________ Do You Yahoo!? Yahoo! Photos - 35mm Quality Prints, Now Get 15 Free! http://photos.yahoo.com/