Composite app question

Hello,

I am very, very new to composite apps and am feeling my way slowly. I think I’m lacking some basic background hence the question. I have a page containing a navigator as one component and I want to change the view based on the selection in another component (much like you would do in a frameset).

Can someone let me in to this secret? How do you change the view a component is looking at? The mail client does it but I can’t work out how.

Thanks