ActivationChanging プロパティ (DropDownClientEvents)

// The client event 'ActivationChanging' takes two parameters sender and e
// sender  is the object which is raising the event
// e is the DropDownActivationEventArgs
function WebDropDown_ActivationChanging(sender, e) {

    //Gets the new active DropDownItem object
    var newActiveItem = e.getNewActiveItem();

    //Gets the text of the new active item
    var newItemText = newActiveItem.get_text();

    if (!confirm("Are you sure you want to activate the item '" + newItemText + "'?"))
        //Cancels the ActivationChanging event
        e.set_cancel(true);
        
        
}