//Fade duration
var duration = 5;

var isLeft = true;

var valueOne =1;
var valueTwo =2;


addLoadEvent(setTimeout("setPhotos();", duration*1000));

function addLoadEvent(func) 
{
  var oldonload = window.onload;
  if (typeof window.onload != 'function') 
  {
    window.onload = func;
  } 
  else 
  {
    window.onload = function() 
	{
      if (oldonload) 
	  {
        oldonload();
      }
      func();
    }
  }
}
function CustomRandom()
{
	
	  var rand_no = Math.random();
	  rand_no = rand_no * 15;
	  return Math.ceil(rand_no);
}


	
function setPhotos()
{
	var div;
	
	if(isLeft)
	{
		div= $('img1');
		valueOne = CustomRandom();
	}
	else
	{
		div= $('img2');
		valueTwo = CustomRandom();
	}
	
	while(valueOne == valueTwo)
	{
		if(isLeft)
		{
			valueOne = CustomRandom();
		}
		else
		{
			valueTwo = CustomRandom();
		}
	}
	
	var newImage = isLeft ? valueOne : valueTwo;
	div.setStyle({backgroundImage:'url("images/img'+ newImage +'.jpg")'}); 
	
	isLeft = !isLeft;
	
	setTimeout("setPhotos();", duration*1000);
}