วิธี sum ค่า textbox แบบ Multiple โดยใช้ JavaScript เขียนแบบใหนได้บ้างครับ รบกวนพี่ๆดูให้หน่อยครับ

<script language="javascript">

	function OpenPopup(intLine)
	{
		window.open('quotation_select.php?Line='+intLine,'myPopup','width=1300,height=450,toolbar=0, menubar=0,location=0,status=1,scrollbars=1,resizable=1,left=10,top=100');
	}


	function CreateNewRow()
	{
		

		var intLine = parseInt(document.frmMain.hdnMaxLine.value);		
		intLine++;
		
			
		var theTable = document.getElementById("tbExp");
		var newRow = theTable.insertRow(theTable.rows.length)
		newRow.id = newRow.uniqueID

		var newCell
		
		//*** Column No ***//
		newCell = newRow.insertCell(0);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center>"+intLine+"</center>";

		//*** Column CustomerID ***//
		newCell = newRow.insertCell(1);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" STYLE=\"width:95%;\" NAME=\"txtpart_number_"+intLine+"\"  ID=\"txtpart_number_"+intLine+"\" VALUE=\"\"></center>";

		//*** Column part_description ***//
		newCell = newRow.insertCell(2);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" STYLE=\"width:98%;\" NAME=\"txtpart_description_"+intLine+"\"  ID=\"txtpart_description_"+intLine+"\" VALUE=\"\"></center>";

		//*** Column QTY ***//
		newCell = newRow.insertCell(3);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" STYLE=\"width:50%; text-align:right;\" NAME=\"txtQTY_"+intLine+"\" ID=\"txtQTY_"+intLine+"\"  VALUE=\"\"> Pc.</center>";
		
		//*** Column part_selling_price ***//
		newCell = newRow.insertCell(4);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\"STYLE=\"width:95%; text-align:right;\" NAME=\"txtpart_selling_price_"+intLine+"\" ID=\"txtpart_selling_price_"+intLine+"\"  VALUE=\"0.00\"></center>";
		
		//*** Columnpart_discount ***//
		newCell = newRow.insertCell(5);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" STYLE=\"width:75%; text-align:right;\" NAME=\"txtpart_discount_"+intLine+"\"  ID=\"txtpart_discount_"+intLine+"\" VALUE=\"0.00\"> %</center>";
	
			//*** Column part_amount ***//
		newCell = newRow.insertCell(6);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" STYLE=\"width:94%;  text-align:right;\" NAME=\"txtpart_amount_"+intLine+"\"  ID=\"txtpart_amount_"+intLine+"\" VALUE=\"0.00\"></center>";	

			//*** Column Add ***//
		newCell = newRow.insertCell(7);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		//newCell.setAttribute("OnClick", "OpenPopup('"+intLine+"')");
		newCell.innerHTML = "<center><INPUT TYPE=\"BUTTON\" NAME=\"btnPopup_"+intLine+"\"  ID=\"btnPopup_"+intLine+"\" VALUE=\"...\" OnClick=\"OpenPopup('"+intLine+"')\"></center>";	
	
		document.frmMain.hdnMaxLine.value = intLine;
		
		
	
	}
	
	function RemoveRow()
	{
		intLine = parseInt(document.frmMain.hdnMaxLine.value);
		if(parseInt(intLine) > 0)
		{
				theTable = document.getElementById("tbExp");				
				theTableBody = theTable.tBodies[0];
				theTableBody.deleteRow(intLine);
				intLine--;
				document.frmMain.hdnMaxLine.value = intLine;
		}	
	}	

	function GenerateRow()
	{
		var intRows = parseInt(document.frmMain.txtCount.value);
		for(i=0;i<intRows;i++)
		{
			 CreateNewRow();
		}
	}

	
</script>