An event is an activity that happens on the web document.  More frequently, multiple inputs are received from the user at once through html form.  The user creates events while interacting  with the DHTML form elements.  Dynamic HTML with the event model exists so that scripts can respond to user interactions and change the page accordingly.  This makes Web applications more responsive and user friendly.  With the event model, scripts  can respond to a user  who is moving the mouse, scrolling up or down the screen or entering keystrokes.  For example the following are some examples of events.

• The HTML document is loaded to the browser.
• The button on the web page is clicked
• A key is pressed
• A button (left/right) of the mouse is clicked
• An option is selected on the selection box of a form
• A radio button is selected
• A check box is set or rest
• Mouse is moved on over an element