Hiding custom buttons in CRM 4.0 Toolbar

var ULListItems = document.getElementById("mnuBar1").rows[0].cells[0].getElementsByTagName("UL")[0].getElementsByTagName("LI");
for(var i=0; i -1)
   {
       ULListItems[i].style.display = "none";
   }
}

from here: http://kennyvaes.wordpress.com/2009/02/03/hiding-custom-buttons-in-crm-40-toolbar/