In our last article we left off with the OnKeyUp function, which is triggered when a user releases a key on the keyboard. We will continue discussing the various JavaScript events in this article, and hopefully finish them in the next tutorial. So grab yourself some coffee and let’s get to work.
OnLoad and OnMouse JavaScript Events - OnMouse Events (Page 2 of 6 )
OnMouse events trigger based upon the user's mouse clicks. There are five in total, starting with the OnMouseDown event.
OnMouseDown
An OnMouseDown event is triggered when the user clicks a mouse button. In the following example, we create a program that will trigger a pop-up alert box to tell the user which element they are clicking on.
<html>
<head>
<script type="text/javascript">
function dontclickme(e)
{
var click
if (!e) var e = window.event
if (e.target) click = e.target
else if (e.srcElement) click = e.srcElement
if (click.nodeType == 3)
click = click.parentNode
var tname
tname=click.tagName
alert("Quit clicking on my " + tname + " element!")
}
</script>
</head>
<body onmousedown="dontclickme(event)">
<h1>Don't you dare click me!</h1>
<p>You may have clicked on the header...but you better not click here!</p>
<input type="submit" value="Click and you will get what for!">
</body>
</html>
In the above example if the user clicks on the phrase “Don’t you dare click me!”, a pop-up will appear with the following text: "Quit clicking on my H1 element!"
If they click on the phrase “You may have clicked on the header…but you better not click here!”, a pop-up will appear, saying: "Quit clicking on my P element."
Lastly, if the user clicks on the submit button, the text "Quit clicking on my Input element!" will appear in a pop-up alert.
A good use for this is if you have a bunch of photos on your site that you don’t want users to be able to download or copy. Simply set the trigger event on each photo with a pop-up alert telling them the images are copyright protected. When they try to save the pictures a pop-up will appear and they will find they are unable to do so.
JavaScript 
OnReset, OnResize and Other JavaScript Events
