While this example talks about descriptions for the items in a menu, it is equally about loading images and changing images in a page. For example, when an item is selected in the menu, an image (showing a description of the item) appears on the right of the menu. The images are changed according to what is selected in the menu. So while the application is one of showing descriptions of menu items, the principle is changing images on a page.
Select a page from the menu above, and then: Go to URL
Click here to view the code!