var topover_timeout= null;
var topover_max= 6;
////////////////
function topover(idn, idn2) {
  if (!document.getElementById) return;
  if (topover_timeout) clearTimeout(topover_timeout);
  if (!idn) {
	topover_timeout= setTimeout('topover(-1, 0)', 900);
	return;
  }
// alert(idn2);
  for (var i=1; i<=topover_max; i++) {
	var elem= document.getElementById('topmenu' + i);
	if (elem) {
		elem.style.visibility= (i==idn || i==idn2) ? 'visible' : 'hidden';
	}
  }
}