// JavaScript Document

function addEvent(obj, evType, fn, useCapture){
  if (obj.addEventListener){
    obj.addEventListener(evType, fn, useCapture);
    return true;
  } else if (obj.attachEvent){
    var r = obj.attachEvent("on"+evType, fn);
    return r;
  } else {
    new Function;
  }
}

function rollup(){
  var l = document.getElementsByTagName('img');
  for(i=0;i<l.length;i++){
    if(l[i].getAttribute('roll')) {
      addEvent(l[i],'mouseover',swap2);
      addEvent(l[i],'mouseout',swap2);
    }
  }
}

function swap2(){
  suffix = '1';
  n = this.src;
  if(n.substring(n.length-(suffix.length+4)) == suffix+'.png') {
    this.src = n.substring(0,n.length-(suffix.length+4))+'.png';
  } else {
    this.src = n.substring(0,n.length-4)+suffix+'.png';
  }
}

window.onload = rollup;