function getObj(name)
{
  if (document.getElementById)
  {
  this.obj = document.getElementById(name);
this.style = document.getElementById(name).style;
  }
  else if (document.all)
  {
this.obj = document.all[name];
this.style = document.all[name].style;
  }
  else if (document.layers)
  {
   this.obj = document.layers[name];
   this.style = document.layers[name];
  }
}

function getRandomIdx(anArr) {
	return Math.round( (anArr.length - 1) * Math.random() );
}

function loadRandomImg(imgArr, anImg) {
		var img = new getObj(anImg);
		idx = getRandomIdx(imgArr);
		img.obj.src = imgArr[idx];
}