How do I saved an edited recording as an MP3 file?

Please help me. I just received a copy of Audacity from a very helpful person at FreeConferenceCall (FCC) to simply edit out the words: “This call is being recorded” out of the very beginning of my first recorded call using FCC, but I can’t get it saved as an MP3 file… It will only save as a .xml file which is useless to me. Please tell me ASAP how to save this edited file as a MP3. Please send your answer 'anitahermesch@helloworld.com

Thank you. Please send an answer as quickly as possible. It’s 3:30PM ON fRI, ocT 2.
Anita Hrmesch

You will get a quicker response if you post in the relevant part of the forum.

See here: http://audacityteam.org/help/faq?s=files&i=aup