private void btnAngebotReport_Click(object sender, EventArgs e)
 {
     if (dgvAngebot.SelectedCells.Count > 0)
     {
         foreach (DataGridViewRow row in dgvAngebot.SelectedRows)
         {
             int angebotID = Convert.ToInt32(row.Cells[0].Value);
             if (_dokument == null)
             {
                 _dokument             = new Izvjestaji.Angebot(angebot);
                 _dokument.FormClosed += dokument_FormClosed;
                 _dokument.Show();
             }
             else
             {
                 _dokument.Activate();
             }
         }
     }
 }
 void dokument_FormClosed(object sender, FormClosedEventArgs e)
 {
     _dokument = null;
 }