รบกวนช่วยดูโค้ดให้หน่อยครับ จะจำกัด การเพิ่มตาราง และ คำนวณผลรวม

function cal(){ //ใช้คำนวณ ช่อง qty_ คูณกับ ช่อง pu_ ไปแสดงผลที่ช่อง ap_ 
var path = document.checkform;
var result = parseFloat(path.qty_.value) * parseFloat(path.pu_.value);
path.ap_.value = result;
}

function CreateNewRow()
	{
		var intLine = parseInt(document.checkform.hdnMaxLine.value);
		intLine++;
			
		var theTable = document.all.dataTable
		var newRow = theTable.insertRow(theTable.rows.length)
		newRow.id = newRow.uniqueID

		var newCell
		
		//*** Column 1 ***//
		newCell = newRow.insertCell(0);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" SIZE=\"50\" NAME=\"des_"+intLine+"\"  ID=\"des_"+intLine+"\" VALUE=\"\"></center>";

		//*** Column 2 ***//
		newCell = newRow.insertCell(1);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" SIZE=\"4\" NAME=\"qty_"+intLine+"\" ID=\"qty_"+intLine+"\"  VALUE=\"\" onblur=\"cal()\"></center>";
		
		//*** Column 3 ***//
		newCell = newRow.insertCell(2);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" SIZE=\"8\" NAME=\"pu_"+intLine+"\"  ID=\"pu_"+intLine+"\" VALUE=\"\" onblur=\"cal()\"></center>";
		
		//*** Column 4 ***//
		newCell = newRow.insertCell(3);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" SIZE=\"8\" NAME=\"ap_"+intLine+"\"  ID=\"ap_"+intLine+"\" VALUE=\"\"></center>";
		
		//*** Column 5 ***//
		newCell = newRow.insertCell(4);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" SIZE=\"5\" NAME=\"weig_"+intLine+"\"  ID=\"weig_"+intLine+"\" VALUE=\"\"></center>";
		
		//*** Column 6 ***//
		newCell = newRow.insertCell(5);
		newCell.id = newCell.uniqueID;
		newCell.setAttribute("className", "css-name");
		newCell.innerHTML = "<center><INPUT TYPE=\"TEXT\" SIZE=\"5\" NAME=\"pack_"+intLine+"\"  ID=\"pack_"+intLine+"\" VALUE=\"\"></center>";
				document.checkform.hdnMaxLine.value = intLine;
	}