or

function GridCreated(sender, args)
{
var grid = sender;
var masterTable = sender.get_masterTableView();
masterTable.selectAllItems(true);
}
<telerik:RadGrid ID ="CandidatesGrid" runat="server" ShowStatusBar="false" AllowPaging="True" AllowSorting="True" PageSize="3" AllowMultiRowSelection="True" GridLines="None" Skin="Outlook" EnableAjaxSkinRendering="true" Width="100%" OnItemCreated="CandidatesGrid_ItemCreated"> <MasterTableView Width="100%" ShowHeader="false" ClientDataKeyNames="ID" GroupLoadMode="Client" AutoGenerateColumns="false" CommandItemDisplay="top"> <CommandItemTemplate> <table> <tr> <td> <label id="lblSelectJobs" runat="server" >Select Jobs</label> </td> <td> <asp:LinkButton ID="lnkSelectAll" runat="server" CommandName="SelectAll" Style="" OnClientClick="SelectRows">Select All</asp:LinkButton> </td> <td> <label id="lblLinkSeparater" runat="server">|</label> </td> <td> <asp:LinkButton ID="lnkDeSelectAll" runat="server" CommandName="DeSelectAll" Style="">DeSelect All</asp:LinkButton> </td> </tr> </table> </CommandItemTemplate> <Columns> <telerik:GridClientSelectColumn UniqueName="ClientSelectColumn" AutoPostBackOnFilter="true" ItemStyle-VerticalAlign="Top"/> <telerik:GridBoundColumn Visible="False" DataField="ID" UniqueName="ID" ItemStyle-Width="0" /> <telerik:GridBoundColumn HeaderText="JobDetails" DataField="JobDetails" UniqueName="JobDetails" /> </Columns> </MasterTableView> <ClientSettings EnableRowHoverStyle="true"> <Selecting AllowRowSelect="True" /> <ClientEvents OnRowSelected="GetSelectedNames" OnGridCreated="GridCreated"/> </ClientSettings> </telerik:RadGrid>
switch (PageIndex) { case 1: RadWindow Window1; Window1 = (RadWindow)Page.Master.FindControl("wndWindow1"); Window1.VisibleOnPageLoad = true; break; case 2: RadWindow Window2; Window2 = (RadWindow)Page.Master.FindControl("wndWindow2"); Window2.VisibleOnPageLoad = true; break; }