public void saveAK() {
    JFileChooser chooser=new JFileChooser();
    if(Chooser.showsaveDialog(this)==JFile Choose.APPROVE_OPTION)
    {
        try{
            FileWriter fw=new FileWriter(chooser.getSelectedFile().getAbsolutePath());
            PrintWriter pw= new FileWriter(fw);
            for (book.list){
                string[]parts=x.getAuthor().split(" ");
                if(parts[1].charAt(0)>='A' && parts[1].charAt(0)<= 'K')
                    pw.println(""+x);
            }
            fw.close();
        }catch (IOException ex){}
    }
  }