In the asp code
function OnClientClose(){
$find("<%= RadAjaxPanel1.ClientID %>").ajaxRequest();
}
<telerik:RadWindowManager RenderMode="Lightweight" ID="RadWindowManager1" runat="server">
<Windows>
<telerik:RadWindow RenderMode="Lightweight" ID="AddBaseDialog" runat="server" Title="Add Base Quantity (Each, Sample)" Height="300px" OnClientClose="OnClientClose"
Width="500px" Left="150px" ReloadOnShow="true" ShowContentDuringLoad="false" VisibleStatusbar="false"
Modal="true">
</telerik:RadWindow>
</Windows>
In the Code Behind
Private Sub RadAjaxPanel1_AjaxRequest(sender As Object, e As AjaxRequestEventArgs) Handles RadAjaxPanel1.AjaxRequest
RadGrid1.MasterTableView.SortExpressions.Clear()
RadGrid1.MasterTableView.GroupByExpressions.Clear()
RadGrid1.Rebind()
End Sub