MultiView ActiveViewIndex Problem

 Hi all, I have a multiview control (as firmaSecenekleri) in my asp.net form and this multiview has 5 view. When the event (shown below) is triggered the view that I want it to be appeared doesn't appear. It was perfectly fine before but now it isn't. How can I fix this problem? Or as an alternative solution is it possible that I can make a view active by giving its id? Sorry if my English is bad, thanks for your answers...

 
protected void BOnaylananIndirimler_Click(object sender, EventArgs e){
firmaSecenekleri.ActiveViewIndex = 2;
loadOnaylananIndirimler();
}  
...