javaScript Introduction

Javascript is a scripting language based on the concept of prototype-based programming. The language is best known for its use in websites as client-side JavaScript. JavaScript was originally developed by Brendan Eich of Netscape under the name Mocha, later LiveScript, and finally renamed to JavaScript.
JavaScript is a prototype-based scripting language with a syntax loosely based on C. Like C, the language has no input or output constructs of its own.
Why should a webpage author use JavaScript in addition to HTML?
* Javascript adds user interactivity.
* Javascript enhances visual displays.
* Javascript allows client-side user form validation.
* Javascript provides more seamless integration with user plug-ins.
* Javascript allows access to some system information that HTML does not.
Why would you want to learn to program in JavaScript when there are so many canned scripts available for cutting and pasting into your own pages. Here are a few good reasons:
* Sometimes you want to customize a canned program to make it unique.
* Some functions that you want to accomplish have not been written yet.
* Many scripts are browser-centric (notably MSIE) or out of date.
* JavaScript is cross-platform. You can write programs that work on Windows, MacIntosh and Linux systems.
* Application users do not have to bother with downloading a JavaScript application, they just access your webpage. And version control is simple as there is one active version -- the one on your website.
* The JavaScript language syntax is similar to that of C and Java so it makes a great starting point on a programming career.
* No proprietary development system is required. A simple editor is all that you need to write Javascript code. A browser is all that is needed to run JavaScript.
* JavaScript code is open source and freely available.