browser = navigator.appName;
  browserVer = parseInt(navigator.appVersion);
    if (browser == "Netscape" && browserVer >= 3)
      preload = "true";
    else if (browser == "Microsoft Internet Explorer" && browserVer >=3)
      preload = "true";
    else
      preload = "false";
// set up graphics
if (preload == "true") 

{
  // onMouseOver
  gue1 = new Image; gue1.src = "spring_images/guestbook1.gif";
  gal1 = new Image; gal1.src = "spring_images/gallery1.gif";
  pos1 = new Image; pos1.src = "spring_images/postcard1.gif";
  tou1 = new Image; tou1.src = "spring_images/tour1.gif";
  cam1 = new Image; cam1.src = "spring_images/harbor_cam1.gif";

  // onMouseOut
  gue2 = new Image; gue2.src = "spring_images/guestbook2.gif";
  gal2 = new Image; gal2.src = "spring_images/gallery2.gif";
  pos2 = new Image; pos2.src = "spring_images/postcard2.gif";
  tou2 = new Image; tou2.src = "spring_images/tour2.gif";
  cam2 = new Image; cam2.src = "spring_images/harbor_cam2.gif";
}

// swap images depending on cursor position over an href
function ImgChange(ImgRef,ImgName) {
  if (preload == "true") {
    document.images[ImgRef].src = eval(ImgName + ".src");
  }
}