var inum = 2;


images = new Array();
images[0] = "images/bg_frotas3.jpg";
images[1] = "images/bg_frotas4.jpg";


// Deactivate cloaking device -->

window.onload=function swapBackground(){
	var randomnumber=Math.floor(Math.random()*inum);
	var div = document.getElementById('background');
	if(randomnumber!=1){
		div.style.background='url('+images[randomnumber]+') no-repeat';
	}else{
		div.style.background='url('+images[1]+') no-repeat';
	}
	
	
}