ถ้าต้องการ sum จำนวน Qty จะต้องทำยังไงอ่ะค่ะ ตามโค้ดและไฟล์ภาพเลยน่ะค่ะ

<%@LANGUAGE="VBSCRIPT" CODEPAGE="874"%>
<!--#include file="Check_Double_Enter.asp" -->
<!--#include file="Connections/Plastic_db.asp" -->
<%	

	Dim Doc_No,Doc_Type,ItemNo,PartNo,PartName,Qty,DDate,Check_Out
	Dim Contact_ID
	Dim Lot_No
	Dim Chk_Out

	Doc_No=Request.Form("Doc_No")
	Doc_Type=Request.Form("Doc_Type")
	PartNo=Ucase(Request.Form("PartNo"))
	Qty=Request.Form("Lot_Qty")
	Lot_No=Request.Form("Lot_No")

	if Request.Form("Submit")="Submit" then 
		Set Conn = Server.CreateObject("ADODB.Connection")
		Conn.Open MM_plastic_db_STRING
		Set rs = Server.CreateObject ("ADODB.Recordset")
		SQL = "Select * From Transection_Sub Where Doc_No='"+Doc_No+"' and Doc_Type='"+Doc_Type+"' "
		SQL = SQL+" and PartNo='"&PartNo&"' and Lot_No='"&Lot_No&"' and Qty='"&Qty&"' "
		rs.Open SQL,Conn,1,3
		if not rs.eof then
			rs("Chk_out")="Y"
			rs.update
			Error1="N"
		else
			Error1="Y"
		end if 	
		rs.close
		conn.close
	end if ' Update

	'Response.Write("<script language='JavaScript' type='text/JavaScript'>")
	'Response.write("window.opener.location.reload();")
	'Response.write("window.
	'Response.write("</script>")

	response.Redirect("Invoice-Check-Out-Main.asp?Doc_No="&Doc_No&"&Doc_Type="&Doc_Type&"&Error1="&Error1)

%>