private void cbProveedor_SelectedIndexChanged(object sender, EventArgs e) { if (cbProveedor.SelectedItem != null) { DataSet dsProveedor = DataUtil.FillDataSet(DataBaseQuerys.Proveedor(DataUtil.GetString(cbProveedor.SelectedItem)), "proveedor"); lblRUC.Text = DataUtil.GetString(dsProveedor.Tables[0].Rows[0], "Proveedor_ruc"); lblTelefono.Text = DataUtil.GetString(dsProveedor.Tables[0].Rows[0], "Proveedor_Telefono"); lblVendor.Text = DataUtil.GetString(dsProveedor.Tables[0].Rows[0], "Proveedor_contacto"); } else { lblRUC.Text = string.Empty; lblTelefono.Text = string.Empty; lblVendor.Text = string.Empty; } }