set_po_box
Description:
Sets the po_box property to po_box.
Set po_box to null to unset the property in the postal address.
Parameters:
| this | |
| po_box | 
           the new P.O. box for the postal address, or   | 
      
Sets the po_box property to po_box.
Set po_box to null to unset the property in the postal address.
| this | |
| po_box | 
           the new P.O. box for the postal address, or   |