private void LoadSavedBill(){
         if(ComboBox_SaveBill.getItemCount() > 0){
            int idxFile = ComboBox_SaveBill.getSelectedIndex();
            String loadFile = saveBillFile + idxFile;
            int count = 1;
            clear_Paid_list();
            clear_table(dm_hoa_don);
            try{
                FileInputStream in = new FileInputStream(loadFile);
                thongbao_text(loadFile, Color.blue);
                try (BufferedReader bufffile = new BufferedReader(new InputStreamReader(in, "UTF8"))){
                    String strLine;
                    strLine = bufffile.readLine();
                    while (strLine != null) {
                        if(strLine.substring(0, 3).equals("==+")){
                            ten_khach_hang.setText(strLine.substring(3));
                        }else if(strLine.substring(0, 3).equals("===")){
                            String sdata[] = strLine.substring(3).split("<>");
                            Vector  sVector = new Vector();
                            sVector.add(count++);
                            sVector.add(sdata[0]);  //ma sp
                            sVector.add(sdata[1]);  //ten sp
                            sVector.add(sdata[2]);  //gia s
                            sVector.add(sdata[3]);  //gia l
                            sVector.add(sdata[4]);  //so luong
                            sVector.add(sdata[5]);  // tien
                            sVector.add(Boolean.TRUE);
                            dm_hoa_don.addRow(sVector);
                            dm_hoa_don.fireTableDataChanged();
                            Paid_MaSP.add(sdata[0]);
                            Paid_TenSP.add(sdata[1]);
                            Paid_GiaSSP.add(Double.parseDouble(sdata[2]));
                            Paid_GiaLSP.add(Double.parseDouble(sdata[3]));
                            Paid_SoLuongSP.add(Double.parseDouble(sdata[4]));
                            Paid_TongGiaSP.add(Double.parseDouble(sdata[5]));
                            //

                        }else if(strLine.substring(0, 3).equals("==-")){
                            No_cu.setText(strLine.substring(3));
                        }
                        strLine = bufffile.readLine();
                    }
                    if(dm_hoa_don.getRowCount() > 0){
                        add_Paid_row();
                    }else{
                        clear_Paid_list();
                        clear_table(dm_hoa_don);
                        thongbao_text("[Lỗi] refresh để làm lại", Color.RED);
                    }
                }
                in.close();
            }catch (Exception e){//Catch exception if any
                thongbao_text("Lỗi" + e.getMessage(), Color.RED);
            }
        }else{
            thongbao_text("Chưa có hóa đơn nào được lựu", Color.blue);
        }
     }