//Edit this line to list all of your background images
var backgroundSrcs = new Array("http://www.eatsleeprace.com/shoppingcart/images/bg_highway.jpg","http://www.eatsleeprace.com/shoppingcart/images/gears.jpg")

function pickimage()
{
//This line picks an image at random from the list you entered above
var bgimage=backgroundSrcs[(Math.round(Math.random()*(backgroundSrcs.length-1)))]

//This line applies the background image to your masthead
document.getElementById("header").style.background = "black url('" + bgimage + "') top center no-repeat";
}