Changing jail's IP automatically

[Grzegorz Junka]

I am using a jail on my laptop and I often connect to different WiFi's, 
which of course assign different IPs to my laptop. I set up the jail by 
adding an alias to wlan0 and I need to update the IP every time I switch 
the WiFi network. Is it possible to create a jail with IP assigned 
dynamically, e.g. from DHCP, or at least switch between predefined IPs 
more easily than by editing /etc/jail.conf?

Grzegorz