<!--
  if (document.images){
     pic1on= new Image(100,25);
     pic1on.src="images/nav1_over.gif";  
     pic1off= new Image(100,25);
     pic1off.src="images/nav1.gif";
	 
	 pic2on= new Image(100,25);
     pic2on.src="images/nav2_over.gif";  
     pic2off= new Image(100,25);
     pic2off.src="images/nav2.gif";
	 
	 pic3on= new Image(100,25);
     pic3on.src="images/nav3_over.gif";  
     pic3off= new Image(100,25);
     pic3off.src="images/nav3.gif";
	 
	 pic4on= new Image(100,25);
     pic4on.src="images/nav4_over.gif";  
     pic4off= new Image(100,25);
     pic4off.src="images/nav4.gif";
   }

function lightup(imgName){
   if (document.images){
      imgOn=eval(imgName + "on.src");
      document[imgName].src= imgOn;
    }
 }

function turnoff(imgName){
   if (document.images){
      imgOff=eval(imgName + "off.src");
      document[imgName].src= imgOff;
    }
 }
//-->