var n = 13;
var f = false;
var b = new Array;
function prel()
{
   	if(document.images)
	{
		for(i=1;i<=n;i++)
		{
			str = 'http://www.nowheretomillionaire.com/images/p' + i + '_o.jpg';
			b[i-1] = new Image();
			b[i-1].src = str;
		}
		f = true;
 	}
}
function on(im)
{
	if (document.images && (f == true)) 
	{
		 document.images[im].src = "http://www.nowheretomillionaire.com/images/"+im+"_o.jpg";
	}
}
function off(im)
{
	if (document.images && (f == true))
		document.images[im].src = "http://www.nowheretomillionaire.com/images/"+im+".jpg";
}