i found a blog but i have a problem. This code line makes me cancer i hope someone can help me. Code line doesnt work, or i didnt work.

Code:
griddoldur();
}
private void button1_Click(object sender, EventArgs e)// EKLE BUTONU
{
cmd = new OleDbCommand();
con.Open();
cmd.Connection = con;
cmd.CommandText = “insert into ogrenci (ogr_no,ogr_ad,ogr_soyad,ogr_tel) values (‘” + tbno.Text +
...