var maxNum = 10;
var rand1 = GetRandom(maxNum);
var time_to_wait = 15000;

bg_images = new Array();
bg_images[1] = "images/backgrounds/background1.jpg";
bg_images[2] = "images/backgrounds/background2.jpg";
bg_images[3] = "images/backgrounds/background3.jpg";
bg_images[4] = "images/backgrounds/background4.jpg";
bg_images[5] = "images/backgrounds/background5.jpg";
bg_images[6] = "images/backgrounds/background6.jpg";
bg_images[7] = "images/backgrounds/background7.jpg";
bg_images[8] = "images/backgrounds/background8.jpg";
bg_images[9] = "images/backgrounds/background9.jpg";
bg_images[10] = "images/backgrounds/background10.jpg";

var bg_image_arr = new Array();

// Ensure you have an array item for every image you are using.
function SetBackground()
{
	var imgIdx = GetRandom(maxNum);
	if(bg_image_arr[imgIdx] != null)
    	document.body.style.backgroundImage = "url(" + bg_image_arr[imgIdx].src + ")";
    else
    	document.body.style.backgroundImage = "url(" + bg_images[imgIdx] + ")";
}
function GetRandom(max)
{
	return Math.round(Math.random() * (max-1)) + 1;
}
function common_initializepage()
{
	SetBackground();
	setTimeout('PreLoadImages()',100);
    setInterval('SetBackground()',time_to_wait);
}
function PreLoadImages()
{
	for(var i = 1; i < bg_images.length; i++)
	{
		if(bg_image_arr[i] == null)
			bg_image_arr[i] = GetImage(bg_images[i]);
	}
}
function GetImage(imgSrc)
{
	var img = new Image();
	img.src = imgSrc;
	return img;
}