//global variables
var imgOn = new Image;
var imgOff = new Image;
var srcOn, srcOff, leftButton, midButton, rightButton; 

//preload info (images)
function preloadInfo(){
	imgOn.src = "images/leftbar-bg_hover.png";
	imgOff.src = "images/leftbar-bg.png";
	getURLs();
}

//image variables (urls)
function getURLs(){
	srcOn = "url(images/leftbar-bg_hover.png)";
	srcOff = "url(images/leftbar-bg.png)";
}

//set object variables
function setIdVariables(){
	leftButton = document.getElementById('sbOne');
	midButton = document.getElementById('sbTwo');
	rightButton = document.getElementById('sbThree');
}

//roll over/out fucntions
function LeftOver(){
	setIdVariables();
	leftButton.style.backgroundImage = srcOn;
}

function LeftOut(){
	setIdVariables();
	leftButton.style.backgroundImage = srcOff;
}

function MidOver(){
	setIdVariables();
	midButton.style.backgroundImage = srcOn;
}

function MidOut(){
	setIdVariables();
	midButton.style.backgroundImage = srcOff;
}

function RightOver(){
	setIdVariables();
	rightButton.style.backgroundImage = srcOn;
}

function RightOut(){
	setIdVariables();
	rightButton.style.backgroundImage = srcOff;
}