how to insert images without IB

Hi everyone! This is probably a silly question, but I've been looking at the 'page control' sample from the apple dev centre, which basically just creates new copies of a template page and changes a label to reflect the page number. I'd like to do the same thing, but use an image instead of a label, and use the page number as part of the filename for the image. For instance page one will load 'xx1.png', page 3 will load 'xx3.png' etc.

I had a quick look at the help file in xcode, and I can't figure out how to display an image using code. If anyone could help me out it would be much appreciated

Thank you in advance!