public static void InsertNewStaff(string Manhanvien, string Maphongkham, string Manhomnhanvien, string Hoten, string Gioitinh, string Tendangnhap, string Matkhau, string Chucdanh, bool Tinhtrang, DateTime Ngaytao)
 {
     using (DB_HMS_Entities staff = new DB_HMS_Entities())
     {
         tbNHANVIEN infor = new tbNHANVIEN();
         infor.MANHANVIEN = Manhanvien;
         infor.MAPHONGKHAM = Maphongkham;
         infor.MANHOMND = Manhomnhanvien;
         infor.HOTEN = Hoten;
         infor.GIOITINH = Gioitinh;
         infor.CHUCDANH = Chucdanh;
         infor.IDDANGNHAP = Tendangnhap;
         infor.MATKHAU = ToMD5(ToMD5(ToMD5(Matkhau)));
         infor.TRANGTHAI = Tinhtrang;
         infor.NGAYTAO = Ngaytao;
         staff.AddTotbNHANVIENs(infor);
         staff.SaveChanges();
     }
 }