//Sửa nhân viên
 public int updatePhieuThuePhong(PhieuThuePhongDTO ptpDTO)
 {
     try
     {
         var querry = (from ptp in htDataContext.phieuthuephongs
                       where ptp.maphieuthue == ptpDTO.Maphieuthue
                       select ptp).FirstOrDefault <phieuthuephong>();
         querry.maphieudat = ptpDTO.Maphieudat;
         querry.username   = ptpDTO.Username;
         htDataContext.SubmitChanges();
         return(1);
     }
     catch
     {
         return(0);
     }
 }
 //Thêm nhân viên
 public int insertPhieuThuePhong(PhieuThuePhongDTO ptpDTO)
 {
     try
     {
         phieuthuephong ptp = new phieuthuephong();
         ptp.maphieuthue = ptpDTO.Maphieuthue;
         ptp.maphieudat  = ptpDTO.Maphieudat;
         ptp.username    = ptpDTO.Username;
         htDataContext.phieuthuephongs.InsertOnSubmit(ptp);
         htDataContext.SubmitChanges();
         return(1);
     }
     catch
     {
         return(0);
     }
 }