All of the code in this month's column was written using a combination of JavaScript and XHTML. If you are unfamiliar with JavaScript, you might want to look at David Flanagan's JavaScript: The Definitiv e Guide, published by O'Reilly. The XHTML is surprisingly readable an d includes many comments and examples of use to developers. You can read it at www.w3.org/TR/xhtml1.

For more information about Google Maps, refer to the Google Maps API site at www.google.com/apis/maps. You also will need to go to that site to get a key, if you decide to sign up for the service.

A short book on the subject, called Pragmatic Google Maps, was written by Scott Davis and published by Pragmatic Programmers (pragmaticprogrammers.com). It contains a lot of good advice for working with Google Maps and puts much of the API documentation into perspective.