[php-list] DELETE query

[Persia]

Hello my friends , 
I have this query but it doesn't work , please inform me if you know .
thanks , Best wishes .

// Check if delete button active, start this
if($del){
for($i=0;$i<$count;$i++){
$delete_id = $checkbox[$i];

$sql6 = "DELETE FROM $tbl_2,$tbl_3 USING $tbl_2,$tbl_3 WHERE
forum_answer.question_id=forum_question.id  AND
forum_question.id='$delete_id'";

$result6 = mysql_query($sql6);
}
}
if($result6){
echo "<meta http-equiv=\"refresh\" content=\"0;URL=CPanel.php\">";
}