//-- ROLLOVER CODE-------------------------------------------------------------
//-- ROLLOVER CODE-------------------------------------------------------------
//-- ROLLOVER CODE-------------------------------------------------------------

var pageRollOvers = [];
var rollOverCounter = 0;

/**
 * Called by document.onLoad to create the rollover objects
 * Createing a rollover object cause it's on image to be
 * preloaded
 * 
 * @param rollOverArray - an array of rollovers records in the form:
 *		  [0] = the name/id of the image object as is in the img tag
 *		  [1] = the off rollover image href
 *	      [2] = the on rollover image href
 */
function createRollOvers(rollOverArray)
{
	for (var i=0; i<rollOverArray.length; i++)
		addRollOver(new RollOver(rollOverArray[i][0], rollOverArray[i][1], rollOverArray[i][2]));
}
/** 
 * helper for createRollOvers
 */
function addRollOver(rollOver){  pageRollOvers[rollOverCounter++] = rollOver;}


/**
 * used by the anchor tags onMouseOver and onMouseOut calls
 * to retrieve the RollOver object that you can call rollOn()
 * or rollOff on
 *
 * @param rolloverName - the name/id of the img href associate
 * 	      with a rollover
 *
 * @return a RollOver object
 */
function getRollOver(rollOverName)
{
	for (var i=0; i<rollOverCounter; i++)
	{
		if (pageRollOvers[i].imageObject == rollOverName)
			return pageRollOvers[i];
	}
	return null;
}

/**
 * RollOver object, a simple object that can toggle
 * the src of an ImageObject
 * 
 * @param imgObject - the name/id of the image as it
 *		  appears in the img tag
 * @param offImageSrc - the href of the off state image
 * @param onImageSrc - the href of the on state image
 */
function RollOver(imgObject, offImageSrc, onImageSrc)
{
	//preload rollover images
	this.preLoadOnImg     = new Image();
	this.preLoadOnImg.src = onImageSrc;

	//object properties	
	this.imageObject = imgObject;
	this.offImageSrc = offImageSrc;
	this.onImageSrc  = onImageSrc;

	//object methods	
	this.rollOn = RollOver_rollOn;
	this.rollOff = RollOver_rollOff;
}

function RollOver_rollOn(){  var img =  DOMGetElement(this.imageObject); if (img)img.src=this.onImageSrc;}
function RollOver_rollOff(){ var img =  DOMGetElement(this.imageObject); if (img)img.src=this.offImageSrc;}