if (document.images)
   {
     pic1on= new Image(86,18);
     pic1on.src="image/eng-overknop-storvatt.gif";  
     pic2on= new Image(60,18);
     pic2on.src="image/eng-overknop-children.gif"; 
     pic3on= new Image(35,17);
     pic3on.src="image/eng-overknop-models.gif"; 
     pic4on= new Image(130,17);
     pic4on.src="image/eng-overknop-wood.gif"; 
     pic5on= new Image(130,18);
     pic5on.src="image/eng-overknop-hotwater.gif"; 
     pic6on= new Image(118,16);
     pic6on.src="image/eng-overknop-building.gif";
     pic7on= new Image(118,17);
     pic7on.src="image/eng-overknop-testing.gif"; 
     pic8on= new Image(78,17);
     pic8on.src="image/eng-overknop-fairs.gif"; 
     pic9on= new Image(53,17);
     pic9on.src="image/eng-overknop-customers.gif"; 
     pic10on= new Image(70,17);
     pic10on.src="image/eng-overknop-brochure.gif"; 
     pic11on= new Image(53,16);
     pic11on.src="image/eng-overknop-contact.gif"; 
     pic12on= new Image(13,13);
     pic12on.src="image/overvlag-engels.gif"; 
     pic13on= new Image(13,13);
     pic13on.src="image/overvlag-belgie.gif"; 
     pic14on= new Image(13,13);
     pic14on.src="image/overvlag-duits.gif"; 
     pic15on= new Image(13,13);
     pic15on.src="image/overvlag-frans.gif";
     pic16on= new Image(13,13);
     pic16on.src="image/overvlag-nederlands.gif"; 
     pic17on= new Image(13,13);
     pic17on.src="image/overvlag-spanje.gif"; 

     pic1off= new Image(86,18);
     pic1off.src="image/eng-knop-storvatt.gif";
     pic2off= new Image(60,18);
     pic2off.src="image/eng-knop-children.gif";
     pic3off= new Image(35,17);
     pic3off.src="image/eng-knop-models.gif";
     pic4off= new Image(130,17);
     pic4off.src="image/eng-knop-wood.gif";
     pic5off= new Image(130,18);
     pic5off.src="image/eng-knop-hotwater.gif";
     pic6off= new Image(118,16);
     pic6off.src="image/eng-knop-building.gif";
     pic7off= new Image(118,17);
     pic7off.src="image/eng-knop-testing.gif";
     pic8off= new Image(78,17);
     pic8off.src="image/eng-knop-fairs.gif";
     pic9off= new Image(53,17);
     pic9off.src="image/eng-knop-customers.gif";
     pic10off= new Image(70,17);
     pic10off.src="image/eng-knop-brochure.gif";
     pic11off= new Image(53,16);
     pic11off.src="image/eng-knop-contact.gif";
     pic12off= new Image(13,13);
     pic12off.src="image/vlag-engels.gif"; 
     pic13off= new Image(13,13);
     pic13off.src="image/vlag-belgie.gif"; 
     pic14off= new Image(13,13);
     pic14off.src="image/vlag-duits.gif"; 
     pic15off= new Image(13,13);
     pic15off.src="image/vlag-frans.gif";
     pic16off= new Image(13,13);
     pic16off.src="image/vlag-nederlands.gif";
     pic17off= new Image(13,13);
     pic17off.src="image/vlag-spanje.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;
    }
 }