function navOn(img1, img2, img3){
  temp1 = document.getElementById(img1);
  temp2 = document.getElementById(img2);
  temp3 = document.getElementById(img3);
  temp1.src = "images/navLeftOn.jpg";
  temp2.className = "navOn";
  temp3.src = "images/navRightOn.jpg";
  return;
 }
 function navOff(img1, img2, img3){
  temp1 = document.getElementById(img1);
  temp2 = document.getElementById(img2);
  temp3 = document.getElementById(img3);
  temp1.src = "images/navLeftOff.jpg";
  temp2.className = "navOff";
  temp3.src = "images/navRightOff.jpg";
  return;
 }