var nav = document.getElementById("nav")

//pre-cache off button images
var offImage = new Array();
offImage[0] = new Image();
offImage[1] = new Image();
offImage[2] = new Image();
offImage[3] = new Image();
offImage[4] = new Image();
offImage[5] = new Image();


//attach a source file to each offImage
offImage[0].src = "images/nav-services-off.gif";
offImage[1].src = "images/nav-about-off.gif";
offImage[2].src = "images/nav-media-off.gif";
offImage[3].src = "images/nav-energy-off.gif";
offImage[4].src = "images/nav-foundation-off.gif";
offImage[5].src = "images/nav-contact-off.gif";



//pre-cache on button images
var onImage = new Array();
onImage[0] = new Image();
onImage[1] = new Image();
onImage[2] = new Image();
onImage[3] = new Image();
onImage[4] = new Image();
onImage[5] = new Image();


//attach a source file to each onImage
onImage[0].src = "images/nav-services-on.gif";
onImage[1].src = "images/nav-about-on.gif";
onImage[2].src = "images/nav-media-on.gif";
onImage[3].src = "images/nav-energy-on.gif";
onImage[4].src = "images/nav-foundation-on.gif";
onImage[5].src = "images/nav-contact-on.gif";



//function that swaps images
function fnOff(i) {
	document.images[i+1].src = offImage[i].src
}
function fnOn(i) {
	document.images[i+1].src = onImage[i].src
}