C#

private void btnRehber_Click(object sender, EventArgs e)
   {
   Form2 rhbForm = new Form2();
   rhbForm.txtYetkili_isim.Text = txtYetkili_adi.Text;
   rhbForm.ShowDialog();
   txtGsm1.Text = rhbForm.txtGsm1.Text;
   txtGsm2.Text = rhbForm.txtGsm2.Text;
   txtNumara.Text = rhbForm.txtNumara.Text;
   }

public class Form2 : Form
   {
   ...
   public string Gsm1
      {
      get { return txtGsm1.Text; }
      } 
   ...
   }

private void btnRehber_Click(object sender, EventArgs e)
   {
   Form2 rhbForm = new Form2();
   rhbForm.txtYetkili_isim.Text = txtYetkili_adi.Text;
   rhbForm.ShowDialog();
   txtGsm1.Text = rhbForm.Gsm1;
   txtGsm2.Text = rhbForm.Gsm2;
   txtNumara.Text = rhbForm.Numara;
   }

private void btnRehber_Click(object sender, EventArgs e)
{
  using (Form2 rhbForm = new Form2()) // Please rename Form2.
  {
    // It's good practice to Dispose of forms. By wrapping
    // this in a using block, the form will be disposed of
    // automatically.
    rhbForm.txtYetkili_isim.Text = txtYetkili_adi.Text;
    if (rhbForm.ShowDialog() == DialogResult.OK)
    {
      // Only update the fields if the user clicked OK.
      txtGsm1.Text = rhbForm.Gsm1;
      txtGsm2.Text = rhbForm.Gsm2;
      frmFirma.txtNumara.Text = rhbForm.Numara;
    }
  }
}

<value>[ ]</value>

int rowIndex = -1;
try
{
    DataGridViewRow row = dataGridView1.Rows
        .Cast<DataGridViewRow>()
        .Where(r => r.Cells[0].Value.ToString().Equals(symbol to be found))
        .First();

    rowIndex = row.Index;
}
catch
{
}