private void btnAdd_Click(object sender, EventArgs e)
 {
     using (FrmContactEditor frm = new FrmContactEditor(new ProductContact()))
     {
         if (frm.ShowDialog() == System.Windows.Forms.DialogResult.OK)
         {
             if (Repository.Sql.ProductContacts.Insert(frm.Contact, this.product))
             {
                 this.product.ProductContacts.Add(frm.Contact);
             }
         }
     }
 }
        private void btnEdit_Click(object sender, EventArgs e)
        {
            ProductContact selected = this.dgvContacts.SelectedItem as ProductContact;

            if (selected == null)
            {
                throw new InvalidOperationException("Please selet a contact to edit");
            }

            using (FrmContactEditor frm = new FrmContactEditor(selected))
            {
                if (frm.ShowDialog() == System.Windows.Forms.DialogResult.OK)
                {
                    Repository.Sql.ProductContacts.Update(frm.Contact);
                }
            }
        }