// deze functie heb ik gevonden op:
// http://www.cryer.co.uk/resources/javascript/script8.htm
// Sytske van Hasselt - 23 juli 2004

function GetParam(name)
{
  var start=location.search.indexOf("?"+name+"=");
  if (start<0) start=location.search.indexOf("&"+name+"=");
  if (start<0) return '';
  start += name.length+2;
  var end=location.search.indexOf("&",start)-1;
  if (end<0) end=location.search.length;
  var result=location.search.substring(start,end);
  var result='';
  for(var i=start;i<=end;i++) {
    var c=location.search.charAt(i);
    result=result+(c=='+'?' ':c);
  }
  return unescape(result);
}