Adding Fax Number Field to Packing/Invoice

[esugrue]

Hi!

I am trying to get the Fax Number field to show on my Packing and Invoice Slips.

I know I have to edit invoice.php and packingslip.php from the admin folder but I don't know to get the fax number to show.

I'd like it to go below:

<tr><td class="main"><?php echo $order->customer['telephone']; ?></td></tr>

So it prints:

Fax Number: (whatever the customer entered)

I thought I might have gotten away with it as

<tr>
            <td class="main"><?php echo $order->customer['fax']; ?></td>
          </tr>

but no.

Thanks
Ernie