function swapImg(id)
{
  var img = document.getElementById(id);

  img.src = "images/nav/" + id + "1.jpg";
}

function swapOut(id)
{
  var img = document.getElementById(id);

  img.src = "images/nav/" + id + ".jpg";
}

function swapInner(id)
{
  var link = document.getElementById(id);

  link.innerHTML = "<img src=\"images/nav/MAC.jpg\" width=\"200\" height=\"310\" border=\"0\" align=\"middle\" />";
}