function swapPicture(targetid)
{
  if (document.images)
  {
	var nextImage=curImage[targetid]+1;
	if (nextImage>=dimages[targetid].length)
	  nextImage=0;
	if (dimages[targetid][nextImage] && dimages[targetid][nextImage].complete)
	{
		var target=document.getElementById(targetid);
  
	  // make sure target is valid.  It might not be valid
	  //   if the page has not finished loading
	  if (target)
	  {
		target.src=dimages[targetid][nextImage].src;
		curImage[targetid]=nextImage;
	  }
	}
  }
}