function setLayer( whichLayer , s){
      var elem, vis;
      if( document.getElementById ) // this is the way the standards work
        elem = document.getElementById( whichLayer );
      else if( document.all ) // this is the way old msie versions work
          elem = document.all[whichLayer];
      else if( document.layers ) // this is the way nn4 works
        elem = document.layers[whichLayer];
      vis = elem.style;
      vis.display = s;
    };
    
    function ustawZakladke(nr){
      setLayer('present_occupant','none');
	  setLayer('past_occupant','none');
      setLayer('comments','none');
      setLayer('description','none');
	  setLayer('party','none');
      setLayer('zakladka1','none');
      setLayer('zakladka2','none');
      setLayer('zakladka3','none');
	  setLayer('zakladka4','none');
      if(nr == 1) setLayer('present_occupant','block');
      if(nr == 2) setLayer('past_occupant','block');
      if(nr == 3) setLayer('comments','block');
	  if(nr == 4) setLayer('description','block');
      if(nr == 1) setLayer('party','block');
      if(nr == 2) setLayer('zakladka2','block');
      if(nr == 3) setLayer('zakladka3','block');
	  if(nr == 4) setLayer('zakladka4','block');
    };