Browser Detection In Javascript(js)

Until one browser remains standing on the web (if ever), browser detection will continue to be part of any good JavaScripter's life. Whether you're gliding a div across the screen or creating an image rollover, it's fundamental that only relevant browsers pick up on your code. In this tutorial we'll probe the navigator object of JavaScript, and show how to use it to perform browser detection, whether the subject is Firefox, Internet Explorer 7, Opera, etc.

http://www.javascriptkit.com/javatutors/navigator.shtml