Question : Wireless access while on wired network

Our office has a wired and wireless network with windows domain, DHCP, authentication, etc.  All of this is behind a sonicwall firewall.  We want to add open wireless access for customers, using a completely separate DSL line, router etc.  But we don't want to allow our employees with laptops and other portable devices to access the open system.  They should only be able to access our closed system while in the office.  How can we set the wireless to exclude them or set the laptops to not connect to the open wireless?  We don't want to disable their wireless card because they will need it when outside the office.

Answer : Wireless access while on wired network

Here is a very basic configuration for a point-to-point T1, and assume that all 24 timeslots are used:

1841:

interface serial 0/0/0
 ip address 192.168.255.254 255.255.255.252
 no shutdown
 service-module T1 clock source internal
!
ip route <remote site network> <mask> 192.168.255.253
ip route 0.0.0.0 0.0.0.0 <ip of local firewall>

2611:
interface serial 0/0
 ip address 192.168.255.253 255.255.255.252
 no shutdown
!
ip route 0.0.0.0 0.0.0.0 192.168.255.254

Done.