var imgList = new Array("bheritage/headerBgImages/resized/bord.jpg","bheritage/headerBgImages/resized/brick.jpg","bheritage/headerBgImages/resized/gov.jpg","bheritage/headerBgImages/resized/red_brick.jpg","bheritage/headerBgImages/resized/shigles.jpg","bheritage/headerBgImages/resized/stone.jpg","bheritage/headerBgImages/resized/stone2.jpg");

var headerElement = document.getElementById('mainHeaderTable');
var bgCounter = Math.floor(Math.random()*imgList.length);
function changeHeaderBg(){
	if(headerElement){
		headerElement.style.backgroundImage = 'url('+imgList[bgCounter]+')';
		if(++bgCounter>=imgList.length){
			bgCounter = Math.round(Math.random()*(imgList.length-1))+1;
		}
		
	}
}
if(headerElement){
	var imageObjs = new Array; 
	for(var i=0;i<imgList.length;i++){
		imageObjs[i] = new Image;
		imageObjs[i].src = imgList[i];
	}
	changeHeaderBg();
}