Sunday, June 8, 2008

Javascript Demystified

Every web surfer knows a classy web site when he sees one, because it has eyecatching
features that make the site outstanding among other sites on the web.
Developers of these sites leave web surfers in awe not by using fancy animation or
provocative pictures, but by using subtle tricks such as fl oating menus and moveable
objects, and by giving the web site the smarts to help a web surfer enter appropriate
information and perform tasks correctly.
Classy web sites attract developers, too, who are like magicians watching a topnotch
magic act, more puzzled than amazed, since what is seen is trickery, not
magic. The question is, how is it done?
No doubt, you’ve raised this same question when visiting a great web site, and
you’ve probably tried to re-create those fancy features using HTML but fell short of
your goal, leaving you wondering what you missed. Now you’ll learn the secret that
master developers use to give web sites the wow factor.
That secret is JavaScript.
JavaScript is a limited-featured programming language used by web developers
to do things that HTML cannot do, such as build dynamic web pages, respond to
events such as a mouse cursor rollover, create interactive forms, validate information
that the visitor enters into a form, control the browser, and much more.
JavaScript is not Java, which confuses many developers who are unfamiliar with
JavaScript. Both are object-oriented programming languages and have Java in their
names, but that’s about as close as they come. You’ll learn the difference in the fi rst
chapter of this book.