Multiples filters: should be wront codes. Which solution?

Question

Hi!

I would like to filter dates with two values once (dates + days + name).

But I receive this error message: "not sufficient parameters..."

    conn.Open();

            OleDbCommand cmd = conn.CreateCommand();

            cmd.CommandType = CommandType.Text;

            cmd.CommandText = "select * from personal where (date between ? and ?) and days = ? and (name = ?)";

            var param1 = new OleDbParameter("@StartDate", OleDbType.Date);

            var param2 = new OleDbParameter("@EndDate", OleDbType.Date);

            var param3 = new OleDbParameter("@name", OleDbType.VarChar); 

            var param4 = new OleDbParameter("@days", OleDbType.VarChar); 

            param1.Value = dataStart.Value.Date;

            param2.Value = dataFinal.Value.Date;

            param3.Value = days.Text;

            param4.Value = name.Text;

            if (dataStart.Value <= dataFinal.Value)

            {

                cmd.Parameters.Add(param1);

                cmd.Parameters.Add(param2);

            }

            else

            {

                cmd.Parameters.Add(param2);

                cmd.Parameters.Add(param1);

            }

            cmd.Parameters.Add(param3);

            cmd.ExecuteNonQuery();

            DataTable dt = new DataTable();

            OleDbDataAdapter da = new OleDbDataAdapter(cmd);

            da.Fill(dt);

            conn.Close();

            dgvRpt2.DataSource = dt;

        }