// JavaScript Document

function roll(img_name, img_src)
   {
   document[img_name].src = img_src;
   }

function attributeSet(elem, attrb, setting)
{
var elemAttrb = elem.getAttributeNode(attrb);
if (elemAttrb)
{
elemAttrb.value=setting;
} else {
elem.setAttribute(attrb, setting);
}
}

function randomClass()
{
var classes = ["bg01","bg02","bg03","bg04","bg05","bg06","bg07","bg08","bg09","bg10","bg11","bg12","bg13","bg14","bg15"]
var index = Math.floor(Math.random() * classes.length);
attributeSet(document.getElementById('myBody'),'class',classes[index]);
}