public static function doesUsernameExist($username) { $safe_username = safe_input::all($username); if (safe_input::is_valid_username($safe_username)) { $db = new database(); $db->select("user", "*", "username= {$safe_username} "); if ($db->number_of_rows() > 0) { return true; } else { return FALSE; } } else { return false; } }