$_GET['givecredit'] = abs( ( int)$_GET['givecredit']);
mysql_query(sprintf("UPDATE `grpgusers` SET `points` =%d , `refers` = %d WHERE `id`= %d",$newpoints,$newrefers,$cp_user->id));
mysql_query(sprintf("DELETE FROM `referrals` WHERE `id`=%d",$_GET['denycredit']));
note :- " use function sprintf in queries "