Java script is a scripting language as you know. But JScript, JQuery and applications made from Java script or in other words made the java script easy to use for the user and readily available. I hope i am right.
attachEvent() instead of addEventListener(); use a global event object instead of passing it to the event listener; call event listeners as global functions instead of invoking them as methods of the object for which they are registered, etc.
jquery.com ... :)