default back button does not appear in uinavigation control

I am working on uinavigation based application. When ever I add a view controller to my project and navigate to it using pussviewcontroler, I dont get default back button on the navigation control. This is happening first time to me, whenever I am creating an application I am not getting default back button Thanks for viewing my question

Thanks Pank开发者_JAVA技巧aj

Usually that happens when the previous UIViewController has no title or a zero-length title. Strangely, the back button still exists (try touching the screen where you expect it to be), but isn't drawn.