There are two styles of gallery pages:
The default style shows all images on the same page. Click on a thumb-nail image to enlarge it. This style works best if your screen resolution is 1024 by 768 pixels or higher. But if your browser does not handle image swaps, then you need to use the alternate style.
The alternate style displays the enlarged images in a separate window. If your screen resolution is 800 by 600 pixels or less, than you should use this style so you don't have to scroll to see the images. But if your browser has a pop-up blocker, then you might need to turn it off temporarily in order to use this style.
Most browsers will work with either style of gallery, so try both styles and use whichever one you prefer. You can change to the other style by clicking on "Switch gallery style" on any Gallery page.
Click your browser's back-button to return to the gallery.