The W3C DOM and JavaScript - JavaScript by Example - page 689

EXPLANATION ( CONTINUED )

12 The getElementsByTagName() method returns a reference to the first img element

in the document and assigns the reference to picture .

13 The getElementById() method returns a reference to the div element that will hold

the caption for an image.

14 Every 5 seconds, an image replacement takes place by changing the value assigned

to the src attribute of the image.

15 Every 5 seconds, the timer will call the startSlideShow() function.

16 The stopSlideShow() function turns off the timer, allowing the user to stop the

slideshow at any time.

Figure 15.50 A sample of the slideshow thumbnails.

15.10.1 JavaScript Libraries

Although the code used in this topic has been written from scratch, beginning with the
very basic JavaScript, once you get going you might want to download some of the use-
ful and free unobtrusive JavaScript code found in libraries on the Web. See http://Java-
Scriptlibraries.com/ for a list of libraries and their links, and for a description of the ten
most popular libraries, go to http://www.ajaxline.com/10-most-popular-JavaScript-frame-
works . They are:

1. jQuery
2. Prototype