The width property refers to the width of a window or frame.
It is set during the RESIZE event to the new width of window or frame being resized.
<html>
<head>
<title>Example of the event.width property</title>
</head>
<body>
<script language = JavaScript>
<!-- function handle(evnt){
alert("An RESIZE event has occurred. The new width of the window is: " + evnt.height); return true;
}
window.onresize = handle;
-->
</script>
Resize browser to see the result
</body>
</html>