Multiple NICs

[Yannack]

Hello,
I have just recently installed FreeBSD release 5.3. I am loving it but 
have a network question.

I have two network cards, one for ethernet, one for wifi. I would like 
to have them both setup to be on DHCP configuration. Now the problem is 
that whatever order i put the setting in rc.conf, i always end up with 
the wifi gateway as my default route. I would like it to be the ethernet 
gateway when available, and only if not available the wifi (as my wifi 
gateway is kind of restrictive). Shortly made: to give the hardwire 
connection priority.
This is what i tried setting in rc.conf:
ifconfig_an0="DHCP"
ifconfig_fxp0="DHCP"
and
ifconfig_fxp0="DHCP"
ifconfig_an0="DHCP"

None of the above work  (ie: they both make the default route go through 
an0 - wifi - and i suspect this is because the wifi dhcp is slower to 
answer than the ethernet one), so i ended up commenting out the wifi 
line (an0) and activating it by hand when needed... However this is 
quite troublesome as it means killing the dhclient running, before 
running another dhclient an0... If anybody has a better suggestion for 
me I would be quite grateful!
Thanks!!!
Yannack