browserName=navigator.appName; 
  browserVer=parseInt(navigator.appVersion);
  if ((browserName=="Netscape" && browserVer>=3) || (browserName=="Microsoft Internet Explorer" && browserVer>=4))    
  version="n3";
  else
    version="n2";
  if (version=="n3")
   {
     max=8;
	    lpon= new Image(15,35);
     lpon.src="../buttons/tl4p.gif";
     lon= new Image(15,35);
     lon.src="../buttons/tl4.gif";
     loff= new Image(15,35);
     loff.src="../buttons/tl3.gif";
     lpoff= new Image(15,35);
     lpoff.src="../buttons/tl3p.gif";
     b2on= new Image(55,35);
     b2on.src="../buttons/ho4.gif";
     b2off= new Image(55,35);
     b2off.src="../buttons/ho3.gif";
     ron= new Image(15,35);
     ron.src="../buttons/tr4.gif";
     rpon= new Image(15,35);
     rpon.src="../buttons/tr4p.gif";
     roff= new Image(15,35);
     roff.src="../buttons/tr3.gif";
     rpoff= new Image(15,35);
     rpoff.src="../buttons/tr3p.gif";
				
     b4on= new Image(55,35);
     b4on.src="../buttons/fa4.gif";
     b4off= new Image(55,35);
     b4off.src="../buttons/fa3.gif";

     b6on= new Image(55,35);
     b6on.src="../buttons/wl4.gif";
     b6off= new Image(55,35);
     b6off.src="../buttons/wl3.gif";

     b8on= new Image(55,35);
     b8on.src="../buttons/fu4.gif";
     b8off= new Image(55,35);
     b8off.src="../buttons/fu3.gif";       
					
 	  }
function lightup(imgNo)
 {
   if (version=="n3")
    {
	leftNo =imgNo -1;
	centreNo=imgNo;
      rightNo=imgNo;
      rightNo++;
      leftName="b"+leftNo;
      centreName="b"+centreNo;
      rightName="b"+rightNo;
      imgOn=eval(centreName + "on.src");
						//document.test.left.value=leftNo;
						//document.test.centre.value=centreNo;
						//document.test.right.value=rightNo;
      document[centreName].src= imgOn;
      if (leftNo>1) {
         imglOn=eval("lon.src");
      }else{
         imglOn=eval("lpon.src");
      }
      document[leftName].src= imglOn;
      if (rightNo<max){
         imgrOn=eval("ron.src");
      }else{
         imgrOn=eval("rpon.src");
      }
      document[rightName].src= imgrOn;
				}
 }
function turnoff(imgNo)
 {
   if (version=="n3")
    {
	leftNo =imgNo -1;
	centreNo=imgNo;
      rightNo=imgNo;
      rightNo++;
      leftName="b"+leftNo;
      centreName="b"+centreNo;
      rightName="b"+rightNo;     
      imgOff=eval(centreName + "off.src");
      document[centreName].src= imgOff;
      if (leftNo>1) {
         imglOff=eval("roff.src");
      }else{
         imglOff=eval("lpoff.src");
      }
      document[leftName].src= imglOff;
      if (rightNo<max){
         imgrOff=eval("roff.src");
      }else{
         imgrOff=eval("rpoff.src");
      }
      document[rightName].src= imgrOff;
    }
 }