or
<button onclick="openWin2();" style="width: 123px" title="Window2">Test2</button><asp:Button ID="Button1" runat="server" Text="Button" />Button1.Attributes.Add("onclick", "javascript:openWin2();return false;")<telerik:RadRibbonBar ID="RadRibbonBar1" runat="server" Skin="Office2010Blue" Width="100%"> <ApplicationMenu Text='<%=Resources.AdminMainMenu.Menu %>' > <Items> <telerik:RibbonBarApplicationMenuItem Text="Exit" ImageUrl="~/Media/Images/Icons/16x16_exit.png" /> </Items> </ApplicationMenu></telerik:RadRibbonBar>