JavaScript and Ajax for the Web: Visual QuickStart Guide, Seventh Edition

Creating Cycling Banners

When you surf the Web, it’s common to see advertising banners that periodically switch between images. Some of these are animated GIF files, which are GIF files that contain a number of frames that play in succession; others are Flash animations. If you want to have a page that cycles through a number of GIFs (either animated or not), you can use JavaScript to do the job, as in Script 4.13.

This example uses three GIFs and cycles repeatedly through them, as shown in Figures 4.10, 4.11, and 4.12. The simple HTML page is shown in Script 4.12.

To create cycling banners:

1.	var thisAd = 0; Our script starts by creating thisAd, which is given its beginning value in this code.
2.	function rotate() { var adImages = new Array("images/reading1.gif","images/reading2.gif","images/reading3.gif"); ...