sorting is not working
<p>when i m trying to sort in grid view without ispostback property then sorintg is done, but when i m using ispoastback property on page_load then it is not working. please suggest me some solution...here is my code</p>

<pre><code>   private string ConvertSortDirection(SortDirection sortDirection)
   {
       string newSortDirection = String.Empty;

       switch (sortDirection)
       {
           case SortDirection.Ascending:
               newSortDirection = "ASC";
               break;

           case SortDirection.Descending:
               newSortDirection = "DESC";
               break;
       }

       return newSortDirection;
   }    

   protected void grd_productMaster_Sorting(object sender, GridViewSortEventArgs e)
   {
       DataTable dataTable = grd_productMaster.DataSource as DataTable;

       if (dataTable != null)
       {
           DataView dataView = new DataView(dataTable);
          dataView = (DataView)Session["dataview"];
           if (Session["dataview"] != null)
           {
               dataView.Sort = e.SortExpression + " " + ConvertSortDirection(e.SortDirection);

              grd_productMaster.DataSource = dataView;

               grd_productMaster.DataBind();
           }
           else
               Response.Write("Dataview is null");

       }
   }
</code></pre>
