var images=new Array(); 
images[0]="images/bg/bg01.jpg"; 
images[1]="images/bg/bg02.jpg"; 
images[2]="images/bg/bg03.jpg"; 
images[3]="images/bg/bg04.jpg"; 
images[4]="images/bg/bg05.jpg"; 
images[5]="images/bg/bg06.jpg"; 
images[6]="images/bg/bg07.jpg"; 
images[7]="images/bg/bg08.jpg"; 
images[8]="images/bg/bg09.jpg"; 
images[9]="images/bg/bg10.jpg"; 
images[10]="images/bg/bg11.jpg"; 

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

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

onload=randomImage;