public static MarkaList Liste(string param, string serial="")
        {
            try
            {
                SqlParameter[] parametre = new SqlParameter[] 
                { 
                    new SqlParameter("@serial", serial),
                    new SqlParameter("@parametre ", param),
                };

                MarkaList markalar = new MarkaList();

                using (SqlDataReader dr = SqlHelper.ExecuteReader("marka_SolPanelListeleme", parametre))
                {
                    while (dr.Read())
                    {
                        markalar.Add(new Markalar(
                           dr.GetInt32(dr.GetOrdinal("id")),
                           dr.GetString(dr.GetOrdinal("marka_adi")).Trim()));
                    }
                }
                return markalar;
            }
            catch (Exception)
            {
                throw;
            }
        }
       public static MarkaList dropDownListele()
        {
            try
            {
                SqlParameter parametre = new SqlParameter("@parametre","AdminDropDown");

                using (SqlDataReader dr = SqlHelper.ExecuteReader("marka_Listele", parametre))
                {
                    MarkaList markaTablo = new MarkaList();
                    while (dr.Read())
                    {
                        Markalar info = new Markalar(
                          dr.GetInt32(dr.GetOrdinal("id")),
                          dr.GetString(dr.GetOrdinal("marka_adi")));
                        markaTablo.Add(info);
                    }

                    return markaTablo;
                }
            }
            catch (Exception)
            {
                throw;
            }
        }