How to get wireless client or ethernet bridge mode to work?

Hello. I tried to get my router to work as a wireless client in my network. I have a Fonera with the dd-wrt firmware as my router that's connected to the internet, and I want my wl-500gp to share my printer and files for my wireless network. By changing the wireless advanced settings to station or ethernet bridge and adding my WEP key and SSID to the relevant places on the wireless settings, I got my asus to connect to my wireless router. It did not get an IP address, however, so no joy.

What other settings are needed for this to work?