if (document.images) {
  var exhibit = new Image();
  exhibit.src = "images/exhibit.gif";
  var exhibit2 = new Image();
  exhibit2.src = "images/exhibit2.gif";
  var resum = new Image();
  resum.src = "images/resum.gif";
  var resum2 = new Image();
  resum2.src = "images/resum2.gif";
  var gall = new Image();
  gall.src = "images/gall.gif";
  var gall2 = new Image();
  gall2.src = "images/gall2.gif";
  var homeshop = new Image();
  homeshop.src = "images/homeshop.gif";
  var homeshop2 = new Image();
  homeshop2.src = "images/homeshop2.gif";
  var homelink = new Image();
  homelink.src = "images/homelink.gif";
  var homelink2 = new Image();
  homelink2.src = "images/homelink2.gif";
  var contac = new Image();
  contac.src = "images/contac.gif";
  var contac2 = new Image();
  contac2.src = "images/contac2.gif";
}

function change(imgName) {
  if (document.images) 
    document.images[imgName].src = eval(imgName + "2.src");
}

function changeback(imgName) {
  if (document.images)
    document.images[imgName].src = eval(imgName + ".src");
}