enter code here



{

    OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=.MSAccessTestDB.accdb");



    private void button1_Click(object sender, EventArgs e)
    {
        con.Open();

        OleDbDataAdapter sda = new OleDbDataAdapter("SELECT * FROM LOGIN where username='" + textBox1.Text + "' and password='" + textBox2.Text + "'", con);
        DataTable dt = new DataTable();
        sda.Fill(dt);
        if (dt.Rows.Count == 1)
        {
            this.Hide();
            Form2 ss = new Form2();
            ss.Show();
        }
        else
        {
            MessageBox.Show("Invalid username/Password");
        }

        con.Close();
    }
}