private void btnApprove_Click(object sender, RoutedEventArgs e)
        {
            if (_supplierMgr != null)
            {
                if (_supplier.IsApproved)
                {
                    MessageBox.Show("Cannot re-add supplier, Supplier already approved", "Supplier already approved", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                    this.Close();
                }
                else
                {
                    try
                    {
                        if (_supplierMgr.ApproveSupplier(_supplier, _userid))
                        {
                            MessageBox.Show("Supplier approved.", "System Updated", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                        }
                        else
                        {
                            MessageBox.Show("Supplier record not altered", "Oops, no record was modified", MessageBoxButton.OK, MessageBoxImage.Hand);
                        }
                    }
                    catch (Exception)
                    {
                        MessageBox.Show("There was an error approving this record. Please try again later", "Oops, something went wrong", MessageBoxButton.OK, MessageBoxImage.Error);
                    }
                    this.DialogResult = true;
                }
            }

            if (_customerMgr != null)
            {
                try
                {
                    if (_customerMgr.ApproveCommercialCustomer(_commercialCustomer, _userid))
                    {
                        MessageBox.Show("Commercial Customer approved.", "System Updated", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                    }
                    else
                    {
                        MessageBox.Show("Commercial Customer record not altered", "Oops, no record was modified", MessageBoxButton.OK, MessageBoxImage.Hand);
                    }
                }
                catch (Exception)
                {
                    MessageBox.Show("There was an error approving this record. Please try again later", "Oops, something went wrong", MessageBoxButton.OK, MessageBoxImage.Error);
                }
            }

            this.Close();
        }