how can I add view controller in existing sample code?

Hi All, I am new to vuforia SDK developement.

Currently when I install sample code, it will directly open the camera view, I want to change this navigation. I want to add a view controller with button "Click", and When I Launch the application it should be apper that View Controller instade of camera view. Than When I click on button "click" it will be open camera view. Can any one tell how should I have to do?

I alrady try the above things, I create a new view controller and added it, in Appdelegate's "didfinishlaunching" method I added myviewcontroller as subview of window, but it gives 40 errors. If anyone tried it or try .. please give the proper solution for this.

Thanks,