or
<telerik:GridTemplateColumn DataField="CellPhone" FilterControlAltText="Filter CellPhoneNumber column" HeaderText="Cell Phone" UniqueName="CellPhoneNumber"> <ItemTemplate> <%# !string.IsNullOrWhiteSpace(Eval("CellPhone")) ? string.Format("{0:(###)###-####}", Convert.ToInt64(Eval("CellPhone"))) : "" %> </ItemTemplate></telerik:GridTemplateColumn>

<script type="text/javascript"> function GetRadWindow() { var oWnd = null; if (window.radWindow) oWnd = window.radWindow; else if (window.frameElement.radWindow) oWnd = window.frameElement.radWindow; return oWnd; } function CloseWindow() { var oWnd = GetRadWindow(); oWnd.close(); } </script>
