var images=new Array(); 
images[0]="images/bg/bg04.jpg";
images[1]="images/bg/bg09.jpg"; 
images[2]="images/bg/bg11.jpg";

var i=Math.floor(Math.random()*images.length); 

function randomImage() 
{ 
	document.getElementById("random").src=images[i]; 
} 

onload=randomImage;