function toggle(target, source)
{
	var e=document.getElementById(target);
	var s=document.getElementById(source);
	if(!e)return true;
  	if(e.style.display=="none")
	{
		e.style.display="block"
		s.src = './bilder/close.gif';
  	} 
	else 
	{
		e.style.display="none"
		s.src = './bilder/open.gif';
  	}
  	return true;
}