var shopArray = new Array(5)
var shopImgArray = new Array(10)

shopArray[0] = "home";
shopArray[1] = "vieworder";
shopArray[2] = "ordhist";
shopArray[3] = "catalogue";
shopArray[4] = "myaccount";
shopArray[5] = "help";
shopArray[6] = "logout";
shopArray[7] = "itemhistory";
shopArray[8] = "orderlists";

//Preload images to image array
for (var i = 0; i < shopArray.length; i++) {
	//Define unhighlighted image
	shopImgArray[(2 * i)+1] = new Image();
	shopImgArray[(2 * i)+1].src = "/images/nav_" + shopArray[i] + "_0.gif";
	//Define highlighted image
	shopImgArray[2 * i] = new Image();
	shopImgArray[2 * i].src = "/images/nav_" + shopArray[i] + "_1.gif";
}						

function rollOn(x){
	document.images["nav" + x].src = shopImgArray[2 * x].src;
}

function rollOff(x){
	document.images["nav" + x].src = shopImgArray[(2 * x)+1].src;
}