Inaccessible due to its protection level!!!!!

[KhoaNguyen]

Hi,

When i compiled these two source files, it gives me an error saying: Inaccesssible Due to its protection level.

------------Base Class-----------------
using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
 
namespace BDIC.Data
{
    class DataAccess
    {
 
        protected string strConnect;
 
        public DataAccess()
        {
 
        }
        /// <summary>
        /// Please see the App.config file
        /// </summary>
 
        static DataAccess()
        {
 
            strConnect = ConfigurationSettings.AppSettings["DbConnection"];
        }
 
 
 
        /// <summary>
        /// Gets a SqlConnection to the local sqlserver
        /// </summary>
        /// <returns>SqlConnection</returns>
        protected SqlConnection GetConnection()
        {
            SqlConnection oConnection = new SqlConnection(strConnect);
            return oConnection;
        }
    }
}
 
 
 
-------inherited Class --------
using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
 
namespace BDIC.Data
{
    class DataOperation:DataAccess
    {
 
 
        public DataOperation()
        {
 
        }
        /// <summary>
        /// inserts a new row in to the table "person"
        /// </summary>
        /// <param name="strName"></param>
        /// <param name="strCName"></param>
        /// <param name="nWeekHour"></param>
        /// <param name="strPassword"></param>
        /// <param name="strEMail"></param>
        /// <param name="nAlreadyIn">returns the number of rows, which fulfill before insertation the condition EMail=strEMail</param>
        public void createJob(string customerName, string customerPhone, string truckMake,
                           string truckModel, string registration, string damageDescription,
                           DateTime deadLine)
        {
            //nAlreadyIn = 0;
            // Establish Connection
            using (SqlConnection oConnection = GetConnection())
            {
 
                    // build the command
                using (SqlCommand oCommand = new SqlCommand("CreateJob", oConnection))
                {
                    oCommand.CommandType = CommandType.StoredProcedure;
 
                    // Parameters
                    SqlParameter paraName = new SqlParameter("@CustomerName", SqlDbType.Char, 50);
 
                        paraName.Value = customerName;
                        oCommand.Parameters.Add(paraName);
 
                        SqlParameter paraCustomerPhone = new SqlParameter("@CustomerPhone", SqlDbType.Char, 50);
                        paraCustomerPhone.Value = customerPhone;
                        oCommand.Parameters.Add(paraCustomerPhone);
 
                        SqlParameter paraTruckMake = new SqlParameter("@TruckMake", SqlDbType.Int, 2);
                        paraTruckMake.Value = truckMake;
                        oCommand.Parameters.Add(paraTruckMake);
 
                        SqlParameter paraTruckModel = new SqlParameter("@TruckModel", SqlDbType.Char, 50);
                        paraTruckModel.Value = truckModel;
                        oCommand.Parameters.Add(paraTruckModel);
 
                    SqlParameter paraRegistration = new SqlParameter("@Registration", SqlDbType.Char, 50);
                    paraRegistration.Value = registration;
                    oCommand.Parameters.Add(paraRegistration);
 
                    SqlParameter paraDeadLine = new SqlParameter("@DeadLine", SqlDbType.Char, 50);
                    paraDeadLine.Value = deadLine;
                    oCommand.Parameters.Add(paraDeadLine);
                    /*
                    SqlParameter paraAlreadyIn = new SqlParameter("@AlreadyIn", SqlDbType.Int, 2);
                    paraAlreadyIn.Direction = ParameterDirection.Output;
                    oCommand.Parameters.Add(paraAlreadyIn);
                    */
 
                    try
                    {
                        oConnection.Open();
                        oCommand.ExecuteNonQuery();
                        //nAlreadyIn = (int)paraAlreadyIn.Value;
 
                    }
                    catch (Exception oException)
                    {
                        throw oException;
                    }
                }
            }
        }
 
 
 
    }
}

when i created a DataOperation object

DataOperation data = new DataOperation() ;

it said BDIC.Data.DataO peration is inaccessbile due to its protection level
and its also said DataOperation contructor does not define ( Do we really need to put anything in there? in my case i dont think i need too) and its last error said "createJob is not in the defintion.


Please explain for me..