function randomBg() {
	var bgArray = ['images/bg_350z.gif', 'images/bg_cts.gif', 'images/bg_mustang.gif', 'images/bg_saab.gif', 'images/bg_vette.gif'];
	
	var num = Math.round(Math.random()*4);
	//alert(bgArray[num]);
	
	var bodyTag=document.getElementsByTagName('body');
	bodyTag[0].style.background = '#000 url("' + bgArray[num] +'") no-repeat top center ';
	
}
if (window.addEventListener) window.addEventListener('load', randomBg, true);
if (window.attachEvent) window.attachEvent('onload', randomBg);