How to add tab page close event handler in ajax builder?

[win98]

I have a tab page with close button. I would like to stop user to close that page is the item id is AAA.
Can you tell me how to achieve that?

[steven]

That's easy.
beforePageClose:function(profile,item,src){   if(item.id == "AAA"){      linb.message("You can NOT close " + item.caption);      return false;   } }