Php login Script? A Question

Hey forum,
I’m looking for a php login script that will direct the person logging in to a specific page/directory depending on their username and password.
i.e Client number 1 & client number 2 wish to view their digital proofs online.
I set up a directory named client one, client two, etc.
I e-mail the clients his/her password and upon logging in they are redirected to their folder.
Any help, links, already make scripts would be helpful. I know this can be done with htaccess, but I would prefer to use php.