function toggle(id) {
  if (!document.getElementById) return;
  var el=document.getElementById(id);
  var on_img=document.getElementById('toggle_on_' + id);
  var off_img=document.getElementById('toggle_off_' + id);
  if (el)
    el.style.display = el.style.display=='block'?'none':'block';
  if (on_img)
    on_img.style.display = on_img.style.display == 'none'?'inline':'none';
  if (off_img)
    off_img.style.display = off_img.style.display == 'none'?'inline':'none';
}

function delayHide(id) {
  window.setTimeout('hide("' + id + '")',500);
}

function show(id) {
  if (!document.getElementById) return;
  var el=document.getElementById(id);
  if (el)
    el.style.display = 'block';
}

function hide(id) {
  if (!document.getElementById) return;
  var el=document.getElementById(id);
  if (el)
    el.style.display = 'none';
}