problem updating data in a datagridview through a query update in access database 2007?

Hello

I need your help, I am developing an app in C# using an Access database(2007), the problem I think is the query update, I have searched over internet but nothing works, I have a datagridview and It has 3 columns the user needs to puts data to the last 2 columns(5 rows), I already do it but when I fill the columns in the datagridview It doenst store the data in the database access. So please I need you help this is my code, help very apreciated :D

 private void btnGuardar_Click(object sender, EventArgs e)
    {

        //using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Databsename.accdb"))
        //{

        OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Databasename.accdb;Persist Security Info=false");


        int grade = 1;
        string x;
        string comment;

            for (int i = 0; i < this.dataGridView4.Rows.Count-1; i++)
            {

                x = dataGridView4.Rows[i].Cells[1].Value.ToString();
                //Console.WriteLine(x);
                MessageBox.Show(x);

                grade = int.Parse(x);


                comment = dataGridView4.Rows[i].Cells[2].Value.ToString();
                MessageBox.Show(comment);

                OleDbCommand cmd = new OleDbCommand("Update archievemnet set grade= @GRADE comment=@COMMENT WHERE idLine =1  ", conn);

                cmd.Parameters.Add(new OleDbParameter("@GRADE", OleDbType.Integer));
                cmd.Parameters["@GRADE"].Value = grade;

                cmd.Parameters.Add(new OleDbParameter("@comment", OleDbType.VarChar));
                cmd.Parameters["@COMMENT"].Value = comment;

                cmd.Connection.Open();
                cmd.ExecuteNonQuery();
                cmd.Connection.Close();
            }



        //}



    }