I am working in OBOUT Grid.I am trying to display an error message while updating the grid but when i click in update link the error message is not diplaying.Please help me to solve this solution.Thank you.This is the script,

protected void grdMain_UpdateCommand(object sender, Obout.Grid.GridRecordEventArgs e)
    {
         if (Convert.ToString(e.Record["Workload_time"]) == "")
        {
            Response.Write("<script language='javascript'>alert('Don't leave this field as blank');</script>");
        }

//Sourcecode

  <obout:Grid ID="grdMain" runat="server" EnableTypeValidation = "true" AutoGenerateColumns="False" OnUpdateCommand="grdMain_UpdateCommand">

<Columns>
<obout:Column DataField="Workload_time" Index="0" >
</Columns>
 </obout:Grid>