Xcode: ViewController.xib or Main.xib

Hi,

i'm reading the excellent Apress book on Beginning IPhone Development. in their examples, they always build their interface by double-clicking the MyProgramViewController.xib.

But when i tried the same and ran the Iphone Simulator later, the interface loaded from MainWindow.xib. i referred few online guides and they'd modified MainWindow.xib itself.

I'm i missing something here? i havent grasped the concept entirely but i'd like to know where the file loads from? and when i should modify the ViewController.xib and when i should modify the MainWindow.xib.

Hope i was clear in explaining my problem.
Thanks!

 

alrighty. Thanks for the help!