img00wzwon = new Image();
  img00wzwon.src = "../img/nav/roelof-on.gif";
  img01wzwon = new Image();
  img01wzwon.src = "../img/nav/felix-on.gif";
  img02wzwon = new Image();
  img02wzwon.src = "../img/nav/madelief-on.gif";
  
  img00wzwoff = new Image();
  img00wzwoff.src = "../img/nav/roelof-off.gif";
  img01wzwoff = new Image();
  img01wzwoff.src =  "../img/nav/felix-off.gif";
  img02wzwoff = new Image();
  img02wzwoff.src = "../img/nav/madelief-off.gif";
 
var previous = "";

function setButton(imageName)
{
        if (document.images && imageName != previous)
   		{
                document[imageName].src = eval(imageName + "on.src");
                if (previous != "")
                        document[previous].src = eval(previous + "off.src");
                previous = imageName;
        }
}

function turnOn(imageName)
{
  if (document.images && imageName != previous)
        document[imageName].src = eval(imageName + "on.src");
}

function turnOff(imageName)
{
  if (document.images && imageName != previous)
        document[imageName].src = eval(imageName + "off.src");
}


function getObj(name) {return (document.getElementById) ? document.getElementById(name).style : ((!document.all) ? document.layers[name] : eval ("document.all."+name+".style;"));}