Question

I have written one JavaScript to Calculate the TotalWeight based on two TextBox integer values. I multiplied these two values and displayed in the 3rd TextBox Using JavaScript. But the problem is, I have one radiobuttonlist, in its selectedindexchanged event, the value I got in the 3rd TextBox gets disappeared. How to solve this?

My JavaScript is

  <script type="text/javascript">
   function TotalWeight()
        {
            var D1 = document.getElementById('<%=txtD1.ClientID%>');
            var SectionWgt = document.getElementById('<%=txtSectionWeight.ClientID%>');
            var TotalWgt = 0*1;
            TotalWgt = parseFloat(D1.value) * parseFloat(SectionWgt.value);

            if(isNaN(TotalWgt))
                document.getElementById('<%=txtTotalWgt.ClientID%>').innerText = "0.000";
            else
                document.getElementById('<%=txtTotalWgt.ClientID%>').innerText = TotalWgt.toFixed(3);
       }
  </script>

  <asp:TextBox ID="txtD1" runat="server" Width="136px" onkeyup="return TotalWeight();"></asp:TextBox>

Answer 1

After you calculate and assign the value to your Total Textbox, then put that value in a hidden field as well, and then on postback reassign that value to the textbox from the hidden Field.