GMadmin help?

$row = mysql_fetch_array(mysql_query(“SELECT userid, usergroupid, salt, password FROM forums_user WHERE username = '”.mysql_escape_string($username)."’"));

Thats the error line that it is having trouble with. Looks like I connected the database etc correctly… but it can’t find the user? What should I change? I am running mybb 1.6! Any help is greatly appreciated!