How to insert integer value in access database?

Question

I am trying to insert Integer value into MS-Access database by using datagridview, but other string values are entered successfully but integer is not. I use debugger also but when debugger come to that line its showing me null value. In my database I use Memo as datatype for Availability, here is my code and possible snapshot

private void dataGridView1_RowLeave(object sender, DataGridViewCellEventArgs e)

{

try

{

if (dataGridView1.IsCurrentRowDirty)

{

string connectionString = null;

connectionString = ConfigurationManager.ConnectionStrings["AccessConnectionString"].ConnectionString;

con.ConnectionString = connectionString;

string cmd1 = "insert into Medicine_Available_Detail(Medicine_Name,Dealer_name,Availability) values(?,?,@Availability)";

OleDbCommand cmd = new OleDbCommand(cmd1, con);

cmd.CommandType = CommandType.Text;

string Medicine_Name = dataGridView1.Rows[e.RowIndex].Cells["Medicine_Name"].Value.ToString();

cmd.Parameters.AddWithValue("@Medicine_Name", Medicine_Name);

string Dealer_name = dataGridView1.Rows[e.RowIndex].Cells["Dealer_name"].Value.ToString();

cmd.Parameters.AddWithValue("@Dealer_name", Dealer_name);

string Availability = dataGridView1.Rows[e.RowIndex].Cells["Availability"].Value.ToString();

cmd.Parameters.AddWithValue("@Availability", Availability);

con.Open();

int n = cmd.ExecuteNonQuery();

con.Close();

if (n > 0)

{

MessageBox.Show("Data Inserted Successfully", "Data Inserted ", MessageBoxButtons.OK, MessageBoxIcon.Information);

}

}

}

catch (Exception ex)

{

Load_data();

dataGridView1.Refresh();

}

}