World Wide Web (WWW) began as a text-only medium. First version doesn't even have the capability to include graphics on a page. Today's Web sites include sound animation, graphics, video and sometimes even useful content! Web scripting languages, like JavaScript, are one of the easiest ways to spice up Web page and to interact with users in new ways, HTML, unlike which is a simple text markup language, which can't respond to user, make decisions or automate repetitive tasks. Web scripting languages enables us to combine scripting with HTML to create interactive Web pages. A script in JavaScript can range from a single line to a full-scale application. JavaScript was developed by Netscape Communications Corporation, the makers of the popular Netscape Navigator Web browser. JavaScript was first Web scripting language to be introduced, and it is by far most popular. Here are a number of things you can do with JavaScript:

• Add changing or scrolling messages to the browser's status line.
• Validate the contents of a form and make calculations.
• Display messages to user, either as part of a Web page or in the alert boxes.
• Create images or animate images which change when you move the mouse over them.
• Detect the browser in use and display different content for different browsers.
• Detect installed plug-ins and notify the user if a plug-in is required.