private void bt_ShowGrid_Click(object sender, EventArgs e)
        {
            try
            {
                string strcon = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = D:\\; Extended Properties = dBase IV; User ID=;Password=";
                OleDbConnection conDB = new OleDbConnection();
                conDB.ConnectionString = strcon;
                conDB.Open();
 
                string query = "Select * from OPLATA";
                OleDbDataAdapter adapter = new OleDbDataAdapter(query, conDB);
                DataSet ds = new DataSet();
                adapter.Fill(ds);
                conDB.Close();
                this.dataGridView1.DataSource=ds.Tables[0];
            }
            catch(OleDbException exp)
            {
                MessageBox.Show("Error: "+exp.Message);
            }
        }