note: you can try the following steps below even if your DSL is down.
(with the computer connected to the westell versalink via ethernet)
try typing
http://192.168.1.1 into your web browser
this is the ip for your wifi router.
(note: If you click on anything that asks for a username/password it will be the username/password for your account when you signed up (most often the same as your username and password for email)).
First I'd check to see if your wifi is enabled by choosing the "configuration" tab and clicking on "wireless".
There will be an option to enable/disable wireless, make sure it's enabled
The next option is labled "Network Name (SSID)"
Make a note of what is in this block, if it is blank, put in something you can remember. This will be the name that shows up for your router when your airport card scans for wifi.
(the other options and what you should change them to)
Mode: mixed
4x: enabled
for now we want to reduce the security settings just to make sure you can connect via wireless (make sure to set these up again when you get everything working).
Authentication type: Open system
Wep security: disabled
Hide SSID: disabled
MAC Address filtering: disabled
after all of your settings look like the ones above click save.
There should be a pop up that comes up, click on "oK"
Your router should reconfigure and reboot.
Once that's done you should be able to physically disconnect the computer from the router and access it via wifi. To do this I'd recommend disabling the airport card, then enable it again, it should do a scan for any wifi spots that are available. If everything worked right, whatever was in your "Network Name (SSID)" box should show up as available to connect to and you should be able to select it.
I'll stop here, and wait to see if that works or not.