// JavaScript Document


//function to preload the images for rollover affects.
function preloadImage(url){
	var i = new Image();
	i.src = url;
	return i;
}

//assign variables to the preloaded images
if (document.images){
	var dogon = preloadImage("images/dog_over.jpg");
	var dogoff = preloadImage("images/dog.jpg");
	var caton = preloadImage("images/cat_over.jpg");
	var catoff = preloadImage("images/cat.jpg");
	var horseon = preloadImage("images/horse_over.jpg");
	var horseoff = preloadImage("images/horse.jpg");
	var bunnyon = preloadImage("images/bunny_over.jpg");
	var bunnyoff = preloadImage("images/bunny.jpg");
}

//function to change the image when a mouse rolls over it
function mouseOn(imgName){
	if(document.images)
		document[imgName].src=eval(imgName + "on.src");
}

//function to return an image to its original state.
function mouseOff(imgName){
	if(document.images)
		document[imgName].src=eval(imgName + "off.src");
}