function toggle(id) {
  if (document.getElementById(id).style['display'] == 'block') {
    document.getElementById(id).style['display']='none';
  }
  else {
    document.getElementById(id).style['display']='block';
  }
}

function popup(url, height, width) {
  var winl = (screen.width-width)/2;
  var wint = (screen.height-height)/2;
  var popup = url.replace(/:|-|_|\?|=|\.|\/|&|%/g, "");
  params = 'scrollbars=1,resizable=1,height=' + height + ',width=' + width + ',left=' + winl + ',top=' + wint;
  newwin = window.open(url, 'popup', params);
  return false;
}