crypt salt question

Hello,



I'm trying to move some app from postgresql to mysql but unable to find out
how to authenticate

against the current crypted passwords with php..



insert to database:



$cset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./";
$salt = substr($cset, time() & 63, 1) . substr($cset, time()/64 & 63, 1);
$password = crypt($password, $salt); //pass crypted version of password
for further processing



$result = pg_query ("INSERT INTO users (username, password) VALUES
('$username', '$password')");



I read the crypt is one way encryption but how to compare the password
entered with the encrypted

version if don't know the salt ??





Thanks,



Andras