var menuButtonActive = null;

  // menu mouseover
  function moMenu( p_eId ) {
    if( menuButtonActive != p_eId ) {
      if( menuButtonActive )
        mInActive( menuButtonActive );
      mActive( p_eId );
    }
  }

  // menu mouseout
  function meMenu( p_eId ) {
    if( menuButtonActive != p_eId ) {
      mInActive( p_eId );
      if( menuButtonActive )
        mActive( menuButtonActive );
    }
  }

  // menu active
  function mActive( p_eId ) {
    document.getElementById(p_eId).className='mButton_over';
  }

  // menu inactive
  function mInActive( p_eId ) {
    document.getElementById(p_eId).className='mButton';
  }