or
<head runat="server"> <script> function ConfirmButton(button, args) { button.set_autoPostBack(false); if( confirm('Are you sure?')) button.set_autoPostBack(true); } </script></head><body> <form id="form1" runat="server"> <telerik:radscriptmanager runat="server" /> <asp:Literal runat="server" ID="ltStatus" /><br/> <telerik:radbutton id="btnCredit" runat="server" text="DoPostback?" onclientclicked="ConfirmButton" onclick="btnCredit_OnClick" /> </form></body><script> function ConfirmButton(button, args) { var setPostback = false; if (confirm('Are you sure?')) setPostback = true; button.set_autoPostBack(setPostback); }</script>