How to get the install config options back?

[Andreas Widerøe Andersen]

Hi,
When I install a new port (Ie. php5) I early get a config options box where
I can choose various add-ons.

However, if the installation fails or I abort it somehow I can't seem to get
the option box back the next time I want to install the port again.

How can I get this "box" back so I can make changes to the installation
options?

Thanks,
Andreas