I tried sha512 or sha-512 but nothing.

Another question- what is the lastest hash? I see examples like Tiger and WHIRLPOOL.

I use SHA512. Here's the code (PHP 5 only):

PHP Code:

$code=hash('sha512',$seed.$string_to_hash); 


So that would explain why I can't use it the same way as sha1()?

PHP Code:

$pass = preg_replace("/[^a-zA-Z0-9]/", "", sha512($_POST['pass'])); 


*I am using PHP5.

Correct. PHP has native functions for md5 and sha1. The others are used via the hash() function.