Help!

I have one of the old Mac Powerbooks [with the clear copper keyboard], and all of the sudden my airport doesn't seem to want to recognize any of the local wireless networks. I did recently plug in an ethernet connection at a different location, and since then it has been acting funny. Did that mess up any of my automatic settings? I dearly need my internet, much like everyone else, to communicate with professors, employers, etc.

Thanks in advance for any help!

-Bill