function showHeaderUnitExplain(){
  document.getElementById("common_header_note_2").style.display = "block";
  document.getElementById("common_header_note_show").style.display = "none";
  document.getElementById("common_header_note_hide").style.display = "inline";
  return(false);
}
function hideHeaderUnitExplain(){
  document.getElementById("common_header_note_2").style.display = "none";
  document.getElementById("common_header_note_show").style.display = "inline";
  document.getElementById("common_header_note_hide").style.display = "none";
  return(false);
}