SqlCommand komut = new SqlCommand("Select * from Tbl_Yonetici Where YoneticiTC=@TC,YoneticiSifre=@sifre", baglan.baglanti());
komut.Parameters.AddWithValue("@TC", textBox1.Text);
komut.Parameters.AddWithValue("@sifre", textBox2.Text);
SqlDataReader oku = komut.ExecuteReader();
while (oku.Read())
{
yonetici ac = new yonetici();
ac.Show();
this.Hide();
}