ขอคำแนะนำการนำข้อมูลจากตารางหนึ่ง มาใส่อีกตารางหนึ่งครับ

<?
$Total = 0;
$SumTotal = 0;
  
$strSQL = "SELECT * FROM customer WHERE IDCard = '".$_POST["IDCard"]."' ";
$objQuery = mysql_query($strSQL);
$objResult = mysql_fetch_array($objQuery);
if($objResult)
{
	$strSQL = "UPDATE customer SET IDCard = '".$_POST["IDCard"]."', Name_cus = '".$_POST["Name_cus"]."', Addr_cus = '".$_POST["Addr_cus"]."'
				,Tel_cus = '".$_POST["Tel_cus"]."',Email = '".$_POST["Email"]."' WHERE ID_cus = '".$_GET["ID_cus"]."' ";
	$objQuery = mysql_query($strSQL) or die(mysql_error());
}
else
{
	$strSQL = "INSERT INTO customer ";
	$strSQL .="(ID_cus,IDCard,Name_cus,Addr_cus,Tel_cus,Email,Status_order) "; 
	$strSQL .="VALUES ";
	$strSQL .="('".$_POST["ID_cus"]."','".$_POST["IDCard"]."','".$_POST["Name_cus"]."' ";
	$strSQL .=",'".$_POST["Addr_cus"]."','".$_POST["Tel_cus"]."','".$_POST["Email"]."','0')";
	$objQuery = mysql_query($strSQL);
}

	$strSQL = "INSERT INTO orders (OrderDate,ID_cus) VALUES 
	('".date("Y-m-d H:i:s")."','".$_POST["ID_cus"]."')";
	  mysql_query($strSQL) or die(mysql_error());

  $strOrderID = mysql_insert_id();
  
  $strSQL = "INSERT INTO payment (PayDate,OrderID,Status_pay) VALUES ('".date("Y-m-d H:i:s")."','".$strOrderID."','1')";
			mysql_query($strSQL) or die(mysql_error());

  for($i=0;$i<=(int)$_SESSION["intLine"];$i++)
  {
	  if($_SESSION["strID_drug"][$i] != "")
	  {
			$strSQL = "INSERT INTO orders_detail (OrderID,ID_drug,Qty) VALUES ('".$strOrderID."','".$_SESSION["strID_drug"][$i]."','".$_SESSION["strQty"][$i]."')";
			mysql_query($strSQL) or die(mysql_error());
	 
      		$strSQL3 = mysql_query("update drug set Amount_drug = Amount_drug - '".$_SESSION["strQty"][$i]."' where ID_drug = '".$_SESSION["strID_drug"][$i]."'");
		} 
	}
			
mysql_close();

	unset($_SESSION["strID_drug"]); 
	unset($_SESSION["img_drug"]); 
	unset($_SESSION["Na1_drug"]); 
	unset($_SESSION["Price_drug"]);
	unset($_SESSION["strQty"]);
	unset($_SESSION["$Total,2"]); 	
	
header("location:order.php?OrderID=".$strOrderID);

?>