So I guess I'm going to need something that will preform this same function but will also check the case. What im doing is making a picture in a directory named the users username.password and registering and signing ARE case sensitive so that means if someone had an account USERNAME PASSWORD and someone else had the accoun username password it will get all jumbled up. Im on windows if that makes any difference (i think it might be the OS) HELP PLEASE!

Well file_exists() certainly must be case sensitive, since that's how all proper operating systems work. Perhaps you're using Windoze, in which case I don't think you can have separate files fred.pwd and Fred.pwd, and this won't work at all.

AAMOF, I don't think it's a good idea to check a username by seeing if a file exists : you should use a database table. I also don't think it's really a good idea to allow usernames distinguished only by case.

Would it work on a linux filesystem? do you know if I can make a linuz file system and still call on it with windows?

Screw it. I just made my registration and sign in case insensitive. thanks anyways!