protected void addHistory(String s){
  if (s.equals("")) {
    return;
  }
  if (m_History.contains(s)) {
    m_History.removeElement(s);
  }
  m_History.add(0,s);
  notifyHistoryChangedListeners();
}

protected void addHistory ( String s ) { if ( s . equals ( "" ) ) { return ; } if ( m_History . contains ( s ) ) { m_History . removeElement ( s ) ; } m_History . add ( 0 , s ) ; notifyHistoryChangedListeners ( ) ; }
adds the given string to the history ( removes duplicates ) .
