Me.WebTab1.ClientEvents.SelectedIndexChanging = "WebTab1_SelectedIndexChanging"
this.WebTab1.ClientEvents.SelectedIndexChanging = "WebTab1_SelectedIndexChanging";
// The client event SelectedIndexChanging takes two parameters sender and e // sender is the object which is raising the event // e is the TabSelectedIndexChangingEventArgs function WebTab1_SelectedIndexChanging(sender, e) { //Gets the new selected index var newIndex = e.get_tabIndex(); //Gets the old selected index var oldIndex = e.get_oldTabIndex(); if(oldIndex == 2) //Cancels the SelectedIndexChanging event e.set_cancel(true); }