function showId(id){
   var mb = document.getElementById(id);
   if (mb) mb.style.visibility = 'visible';
}
function hideId(id){
   var mb = document.getElementById(id);
   if (mb) mb.style.visibility = 'hidden';
}
function openHelp(){
   var mb = document.getElementById('id_page_help');
   if (mb) mb.style.visibility = 'visible';
   document.cookie = "_page_help=1;";
}
function closeHelp(){
   var mb = document.getElementById('id_page_help');
   if (mb) mb.style.visibility = 'hidden';
   document.cookie = "_page_help=0;";
}