if (document.images)
   {
     pic1on= new Image(100,35);
     pic1on.src="images/indrukhome.gif";  
     pic2on= new Image(100,35); 
     pic2on.src="images/indrukvoorb.gif"; 
     pic3on= new Image(100,35);
     pic3on.src="images/indrukserres.gif";
     pic4on= new Image(100,35); 
     pic4on.src="images/indrukonzewerk.gif";
     pic5on= new Image(100,35);
     pic5on.src="images/indrukcontact.gif";  

          
     pic1off= new Image(100,35);
     pic1off.src="images/knophome.gif";
     pic2off= new Image(100,35);
     pic2off.src="images/voorbeelden.gif";
     pic3off= new Image(100,35);
     pic3off.src="images/info.gif";
     pic4off= new Image(100,35);
     pic4off.src="images/werkwijze.gif";
     pic5off= new Image(100,35);
     pic5off.src="images/contact.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;
    }
 }