	var popupHandle;
	function popup(picUrlString, windowWidth, windowHeight)
	{
	  if(popupHandle || popupHandle!=null)
	  {
		if (!popupHandle.closed) popupHandle.close();
	  }
	  popupHandle=null;
	  var x=(screen.width-windowWidth)/2
	  var y=(screen.height-windowHeight)/2
	  var featureString = "toolbar=no,scrollbars=no,resizable=no"
	  featureString = ',left='+x + ',top='+y
	  featureString += ',width='+windowWidth+',height='+windowHeight
	  var htmlString = "<html><head><title>Klik om te sluiten</title></head>"
	  htmlString += "<body marginwidth=0 marginheight=0 leftmargin=0 topmargin=0 bgcolor=black text=\"white\" onclick=\"self.close()\">"
	  htmlString += "<A HREF=\"javascript:window.close();\" title=\"Sluit venster\" >"
	  htmlString += "<IMG SRC=\"" + picUrlString + "\" BORDER=\"0\" WIDTH=" + windowWidth + " HEIGHT=" + windowHeight + "></A>"
	  htmlString += "</body></html>"
	  popupHandle = window.open("" ,"popup",featureString)
	  popupHandle = window.open("" ,"popup")
	  popupHandle.document.clear();
	  popupHandle.document.writeln(htmlString);
	  popupHandle.focus();
	  popupHandle.document.close(); // should trigger the picture loading.
	  return popupHandle;
	}
	function winclose()
	{
	  if (window.popupHandle!=null && !window.popupHandle.closed)
	  {
		window.popupHandle.close();
	  }
	}
	function doNothing(){} 