if (document.images) {
  
  image1on = new Image();
  image1on.src = "images/home-navigation/canitbedone_on.gif";
  
  image2on = new Image();
  image2on.src = "images/home-navigation/provenapps_on.gif";

  image3on = new Image();
  image3on.src = "images/home-navigation/whatis_on.gif";

  image4on = new Image();
  image4on.src = "images/home-navigation/learnmore_on.gif";

  image5on = new Image();
  image5on.src = "images/home-navigation/difference_on.gif";
  
  image6on = new Image();
  image6on.src = "images/home-navigation/app_on.gif";
  
  image7on = new Image();
  image7on.src = "images/home-navigation/sys_on.gif";
  
  image8on = new Image();
  image8on.src = "images/examples/example1-on.gif";
  
  image9on = new Image();
  image9on.src = "images/examples/example2-on.gif";
  
  image10on = new Image();
  image10on.src = "images/home-navigation/contactus-on.gif";
  
  
  image1off = new Image();
  image1off.src = "images/home-navigation/canitbedone_off.gif";

  image2off = new Image();
  image2off.src = "images/home-navigation/provenapps_off.gif";

  image3off = new Image();
  image3off.src = "images/home-navigation/whatis_off.gif";

  image4off = new Image();
  image4off.src = "images/home-navigation/learnmore_off.gif";

  image5off = new Image();
  image5off.src = "images/home-navigation/difference_off.gif";
  
  image6off = new Image();
  image6off.src = "images/home-navigation/app_off.gif";
  
  image7off = new Image();
  image7off.src = "images/home-navigation/sys_off.gif";

  image8off = new Image();
  image8off.src = "images/examples/example1-off.gif";
  
  image9off = new Image();
  image9off.src = "images/examples/example2-off.gif"; 
  
  image10off = new Image();
  image10off.src = "images/home-navigation/contactus-off.gif";
  
}

function turnOn(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "on.src");
  }
}

function turnOff(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "off.src");
  }
}