var selec = '';
 function showSub(id){

  if (selec != '' && selec != id){
   objselec = document.getElementById(selec);
   objselec.style.backgroundImage = 'url(images/bluearrowside.gif)';
   objselecmenu = document.getElementById(selec + 'Down');
   objselecmenu.style.display = 'none';
  }


  tmp = document.getElementById(id + 'Down');
  tmp2 = document.getElementById(id);

  if (tmp.style.display == 'block'){
   tmp.style.display = 'none';
   tmp2.style.backgroundImage = 'url(images/bluearrowside.gif)';
  }else {
   tmp.style.display = 'block';
   tmp2.style.backgroundImage = 'url(images/bluearrowdown.gif)';
  }

   selec = id;

 }