Here is a sample of a pop up alert box. When you click on the words CLICK HERE! below, a box should appear on the screen. This is a good technique for adding clickable definitions to your web page.
Here's another pop up alert box that comes up when the mouse is rolled over the link.
There is another way to have information boxes pop up on the screen called "titles". Put your mouse over the link below and wait a moment. A small box should appear (it looks like the word boxes in cartoons).
PUT YOUR MOUSE ON THIS LINK AND WAIT A MOMENT!