if (document.images) {
  image1on = new Image();
  image1on.src = "../images/navaboutr.gif";

  image1off = new Image();
  image1off.src = "../images/navabout.gif";
  
  image2on = new Image();
  image2on.src = "../images/navscreeningsr.gif";

  image2off = new Image();
  image2off.src = "../images/navscreenings.gif";
  
  image3on = new Image();
  image3on.src = "../images/navservicesr.gif";

  image3off = new Image();
  image3off.src = "../images/navservices.gif";
  
  image4on = new Image();
  image4on.src = "../images/navtestimonialsr.gif";

  image4off = new Image();
  image4off.src = "../images/navtestimonials.gif";
  
  image5on = new Image();
  image5on.src = "../images/navcontactr.gif";

  image5off = new Image();
  image5off.src = "../images/navcontact.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");
  }
}