var dimages=new Array();

var numImages=8;

for (i=0; i<numImages; i++)
{
  dimages[i]=new Image();
  dimages[i].src="./foto/"+(i+1)+".jpg";
}

var curImage=-1;

function swapPicture()
{
  if (document.images)
  {
    var nextImage=curImage+1;

    if (nextImage>=numImages)
      nextImage=0;
    if (dimages[nextImage] && dimages[nextImage].complete)
    {

    var target=0;

    if (document.images.myImage)
        target=document.images.myImage;

    if (document.all && document.getElementById("myImage"))
        target=document.getElementById("myImage");
  
      // make sure target is valid.  It might not be valid
      //   if the page has not finished loading
      if (target)
      {
        target.src=dimages[nextImage].src;
        curImage=nextImage;
      }

      setTimeout("swapPicture()", 4000);

    }
    else
    {
      setTimeout("swapPicture()", 4000);
    }
  }
}

setTimeout("swapPicture()", 4000);