I was surprised that a window opened to show the full jpg. Is this the “wrong” way to do it? Should I put putting each jpg on a separate html page? This was done in a hurry because I had 33 jpgs on the page to do.
As MarPlo says, I would use a Lightbox script for this.
There are plenty available for WordPress if that is what you are using.
This is the one I use: http://wordpress.org/plugins/wp-jquery-lightbox/