Lost WEP Passkey

Hi Everybody
I am new and this is my first post.
I cannot remember my Wep passkey and it is not listed in my keychain. I have an Airport extreme. Can anyone help me. I need the passkey to set up my Pandora radio.
Thank you:

Open up Airport Utilities and set a new password - and while you're there change it to WPA/WPA2.

You should be able to open airport utility and get the password. See this article.
AirPort Utility 5.1 Help: Password-protecting your wireless network

[Edit] Bob is faster on the draw than I am. And a good point - don't bother with WEP.