question about md5()

[dv6cougar]

ok so i know the passwords are encrypted into the database using md5()

now when pulling it uses this code

PHP Code:

 if ($user=$DB_site->query_first("SELECT userid,username,password,cookieuser FROM user WHERE username='".addslashes(htmlspecialchars($username))."'")) {
      if ($user['password']!=md5($password)) {  // check password
        eval("standarderror(\"".gettemplate("error_wrongpassword")."\");");
        exit;
      } 


how does it geht the variable $password ?

i need to hack in a login from somewhere else, how do in decrypt the password from the encryption?

the above came from member.php under if($action=="login") {


thanks alot