JavaScript Tutorial/Document/onmousedown
document.onmousedown
The onMouseDown event handler specifies what should happen when the mouse button is pressed within the Document object.
<html>
<head>
<script language="JavaScript1.2">
<!--
document.onmousedown = myMouseDownHandler;
function myMouseDownHandler() {
alert("A mouse down event took place within the document!");
}
-->
</script>
</head>
<body>
Press the mouse button down within this document.
</body>
</html>