delete ข้อมูลอีกตารางและ update ข้อมูลอีกตารางเขียนยังไงดีครับ

<?php
$objConnect = mysql_connect("localhost","root","12345678") or die("Error Connect to Database");
$objDB = mysql_select_db("project");
//*** Delete Condition ***//
if($_GET["Action"] == "Del")
{
	$strSQL = "DELETE FROM tb_com where sn_com = '".$_GET["sn_com"]."'";
	
	$objQuery = mysql_query($strSQL);
	if(!$objQuery)
	{
		echo "Error Delete [".mysql_error()."]";
	}
	//header("location:$_SERVER[PHP_SELF]");
	//exit();
}
?>


</table> </td>
      <td width="1042" colspan="2" align="center" valign="top"><h5>ลบเครื่องคอมพิวเตอร์ห้อง 4705</h5>
<table width="720" border="1">
<?php
	$objConnect = mysql_connect("localhost","root","12345678") or die("Error Connect to Database");
	$objDB = mysql_select_db("project");
	$strSQL = "SELECT * FROM tb_com where id_room ='4705' order by id_image asc ";
	$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
?>
<tr>
<th width="100"><div align="center">รหัสเครื่องคอมพิวเตอร์</div></th>
<th width="100"><div align="center">แถว</div></th>
<th><div align="center">C1</div></th>
<th><div align="center">C2</div></th>
<th><div align="center">C3</div></th>
<th><div align="center">C4</div></th>
<th><div align="center">C5</div></th>
<th><div align="center">C6</div></th>
<th><div align="center">C7</div></th>
<th><div align="center">C8</div></th>
<th><div align="center">C9</div></th>
<th><div align="center">C10</div></th>
<th><div align="center">C11</div></th>
<th><div align="center">C12</div></th>
<th><div align="center">C13</div></th>
<th><div align="center"></div></th>

</tr>
<?php
	while($objResult = mysql_fetch_array($objQuery))
	{
?>
<tr>
<td width="100"><?=$objResult["sn_com"];?></td>
<td width="100"><?=$objResult["id_image"];?></td>
<td><?=$objResult["c1"];?></td>
<td><?=$objResult["c2"];?></td>
<td><?=$objResult["c3"];?></td>
<td><?=$objResult["c4"];?></td>
<td><?=$objResult["c5"];?></td>
<td><?=$objResult["c6"];?></td>
<td><?=$objResult["c7"];?></td>
<td><?=$objResult["c8"];?></td>
<td><?=$objResult["c9"];?></td>
<td><?=$objResult["c10"];?></td>
<td><?=$objResult["c11"];?></td>
<td><?=$objResult["c12"];?></td>
<td><?=$objResult["c13"];?></td>
<td><a href="JavaScript:if(confirm('ยืนยันการลบ?')==true){window.location='<?php echo $_SERVER["PHP_SELF"];?>?Action=Del&sn_com=<?php echo $objResult["sn_com"];?>';}" class="btn btn-danger btn-sm">ลบ</a></td>


</tr>
<?php
	}
?>