สอบถามหน่อยยค่ะ ส่งค่าโดยไม่ให้รีเฟรชหน้า พอมีแนวการเขียนให้ไหมค่ะ

<?php
ob_start();
session_start();
if($_SESSION['id'] <> "") {	
if(!isset($_SESSION["intLine"]))
{

	 $_SESSION["intLine"] = 0;
	 $_SESSION["strProductID"][0] = $_GET["ProductID"];
	 $_SESSION["strQty"][0] = 1;

	 //header("location:product.php");
	 echo "<script>history.back();</script>";
}
else
{
	
	$key = array_search($_GET["ProductID"], $_SESSION["strProductID"]);
	if((string)$key != "")
	{
		 $_SESSION["strQty"][$key] = $_SESSION["strQty"][$key] + 1;
	}
	else
	{
		
		 $_SESSION["intLine"] = $_SESSION["intLine"] + 1;
		 $intNewLine = $_SESSION["intLine"];
		 $_SESSION["strProductID"][$intNewLine] = $_GET["ProductID"];
		 $_SESSION["strQty"][$intNewLine] = 1;
	}
	 //header("location:product.php");
	 echo "<script>history.back();</script>"; 

}
}else{
  
echo("<script> alert('Please Login !');</script>");
echo "<meta http-equiv='refresh' content='0;url= login.php'>";
  
}
?>

<?/* This code download from www.ThaiCreate.Com */ ?>