// JavaScript Document
var n_l;
var n_r;
var n_images = 29;
var n_seconds = 10;

function initImages()
{
	n_l=Math.floor(Math.random()*n_images)+1;
	n_r=Math.floor(Math.random()*n_images)+1;
	changeLeft(n_l);
	changeRight(n_r);
	setTimeout('rotateRight()', n_seconds*1000);
	setTimeout('preloadImages()', 5);
}

function preloadImages()
{
	if (document.images)
	{
		for (i=1;i<=n_images;i++)
		{
			eval('limage'+i+'= new Image()');
			eval('limage'+i+'.src = \'/images/l'+i+'.jpg\'');
			eval('rimage'+i+'= new Image()');
			eval('rimage'+i+'.src = \'/images/r'+i+'.jpg\'');
		}	
	}
}

function changeLeft(a_n)
{
	document.getElementById('left-page').style.background='url(images/l'+a_n+'.jpg) no-repeat';
}

function changeRight(a_n)
{
	document.getElementById('right-page').style.background='url(images/r'+a_n+'.jpg) no-repeat';	
}

function nextNumber(a_n)
{
	n_next = a_n + Math.floor(Math.random()*(n_images - 1)) + 1;
	if (n_next > n_images)
	{
		n_next = n_next - n_images;	
	}
	return n_next;
}

function rotateRight()
{
	n_r = nextNumber(n_r);
	changeRight(n_r);
	setTimeout('rotateLeft()', n_seconds*1000);
}

function rotateLeft()
{
	n_l = nextNumber(n_l);
	changeLeft(n_l);
	setTimeout('rotateRight()', n_seconds*1000);	
}