I need to know how to add one view contoller as a child of another view controller in objective-c. As of now I am presenting a view controller as a modal of the rootview controller. But I want to change it now. I have 2 view controllers which I am presenting as modals of root view controller. But how can I present them in a different way? How does this parent-children concept work? Please give me some references.
To start with you should read the following:
View Controller Programming Guide
I believe that between the two of them you should be able to learn most, if not all, of what you need to learn about UIViewControllers and view hierarchys.