<!-- Begin
browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);

ns3up = (browserName == "Netscape" && browserVer >= 3);
ie4up = (browserName.indexOf("Microsoft") >= 0 && browserVer >= 4);

if (ns3up || ie4up) {
  image1 = new Image();
  image1.src = "MainImages/MathofFractals.gif";
  image2 = new Image();
  image2.src = "MainImages/mandel.jpg";
  image3 = new Image();
  image3.src = "MainImages/galleries.gif";
  image4 = new Image();
  image4.src = "MainImages/Art_Gallery.jpg";
  image7 = new Image();
  image7.src = "MainImages/formulas.gif";
  image8 = new Image();
  image8.src = "MainImages/Tutorial.jpg";    
  image9 = new Image();
  image9.src = "MainImages/ChallengeMouse.jpg";    
  image10 = new Image();
  image10.src = "MainImages/ChallengeTop.jpg";    
  image11 = new Image();
  image11.src = "MainImages/downloads.gif";
  image12 = new Image();
  image12.src = "MainImages/download.jpg";
  image13 = new Image();
  image13.src = "MainImages/links.gif";
  image14 = new Image();
  image14.src = "MainImages/links.jpg";
  image15 = new Image();
}

function switchpic(img_name,img_src) {
if (ns3up || ie4up) {
document[img_name].src=img_src;
}
}
// End -->