Me.WebTab1.ClientEvents.SelectedIndexChanged = "WebTab1_SelectedIndexChanged"
this.WebTab1.ClientEvents.SelectedIndexChanged = "WebTab1_SelectedIndexChanged";
// The client event SelectedIndexChanged takes two parameters sender and e // sender is the object which is raising the event // e is the TabItemPostBackEventArgs function WebTab1_SelectedIndexChanged(sender, e) { //Gets the postback flag var postBack = e.get_postBack(); //Gets the new selected tab index var tabIndex = e.get_tabIndex(); //Assuming you have a label called labelOutput on the form var label = $get('labelOutput'); label.innerHTML = "Tab with index '" + tabIndex + "' is selected!"; }