Gridview footer value not working with javascript

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ASP.NET

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i m havng a gridview, a previous value lable column called lbl_pre, text box column named txt_pre which is used to make entry , another label named lbl_sum column which will be used for previous value + user enter value
now my lbl_pre + txt_pre value working fine and lbl_sum shown correct output, but total of lbl_sum is not working.

What I have tried:

<script type="text/javascript">

         function Calctotal_pre(PreviousValue, txtvalue, TotalValue)
         {
             var uservalue = parseFloat(document.getElementById(txtvalue).value);
             var TotalVar = document.getElementById(TotalValue);

 var TotalValue = parseFloat(PreviousValue + uservalue );
             TotalVar.innerHTML = TotalValue;

                    var total_allPY = 0;
                     $($("[id*=GvList] [id*=lbl_sum]")).each(function ()
                     {
                         if (!isNaN(parseFloat($(this).val())))
                         {
                             total_allPY += parseFloat($(this).val());
                         }
                     });
           
                     $("[id*=GvList] [id*=lbl_PY_total]").html(total_allPY);
  }
 </script>

----------------CODE PART--------------

protected void GvList_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        { 
 Label lblList = (Label)e.Row.FindControl("lbl_pre");
            PreVal += Convert.ToDecimal(lblList.Text);

 txt_pre.Attributes.Add("onkeyup", "Calctotal_pre(" + PreVal  + ", '" + txtqut.ClientID + "','" + lbl_sum.ClientID + "')");
 }
 }