/*
 *	Rollover
 *
 *	Encapsulate a simple image rollover as an object.
 *
 *	Example of use:
 *
 *		<script type="text/javascript" src="Rollover.js"></script>
 *		<script type="text/javascript">
 *			r = new Rollover("on.gif");
 *		</script>
 *		
 *		<a href="#" onmouseover="r.over('i')" onmouseout="r.out('i')">
 *			<img id="i" src="off.gif" alt="" />
 *		</a>
 *
 *	Optionally, you can also specify the image name when you create the
 *  Rollover object. This binds a Rollover to a particular image and
 *	removes the need to specify the image name each time the Rollover
 *	functions are called.
 *
 *	Afternoon <noon at aftnn.org>, 2004
 *
 */

function Rollover(overSrc, name) {
	this.over_frame = new Image();
	this.off_frame = new Image();

	this.name = name;
	
	// preload rollover frame
	this.over_frame.src = overSrc;
}

Rollover.prototype.over = function (img) {
	if (!img && this.name) img = this.name;
	this.off_frame.src = document.images[img].src;
	document.images[img].src = this.over_frame.src;
}

Rollover.prototype.out = function (img) {
	if (!img && this.name) img = this.name;
	document.images[img].src = this.off_frame.src;
}