Error with popup in VirtualButtons example

Hi everybody,i change the option menu for an alert in the virtualButtons example.but, i try open a new view or open a popup view  (like this: http://www.touch-code-magazine.com/showing-a-popup-window-in-ios-class-for-download/)my idea is put a webpage after touch screen. i try with an alert, and this work OK.But, i try with popup or go to new view, the 'oppacity' is -1 for every tap in the screen and i don't see the view or popup.Any idea?thx :)(sry 4 my english)