JavaScript is useful for making your site more interactive. It gives your pages the ability to respond to events (such as the mouse moving over some text) by making a change in what the user sees (such as revealing more information or changing the format or position of something on the page). It generally does this by dynamically modifying either the HTML or CSS for the page. This is commonly referred to as Dynamic HTML or DHTML for short.

A web page is made up of objects, which can be referenced through the Document Object Model (DOM). JavaScript can directly manipulate these objects to make a page come alive. The beauty of it is that there are huge numbers of scripts that have already been written that you can get for free and use on your site without ever learning how to program. Microsoft calls their implementation of Javascript "JScript", and just as different browsers support CSS differently, there are differences in DOM and Javascript support as well.
To accommodate those people that have JavaScript disabled in their browser, you must ensure that your site functions adequately if the scripts cannot function.

This site uses Javascript and DTHML in the following ways:
  • If you came here from a site that tries to display this site inside of one of its own frames, this page will automatically break out of that frame
  • Some links have formatted tooltips that appear when you move your mouse over them
  • If you click on a link to another site, the new page will open in a new browser tab or window
  • The feedback form will not submit if you haven't entered a correct email adddress
  • The feedback form will send information about what browser you are using and at what screen resolution
  • The various website analytics programs that I use rely on JavaScript to collect information

Categorized Collections of Free Scripts