How do I post and mp3 file?

How do I post a mp3?

Under the reply box there is a an arrow saying Additional Options, click that and you can post a file. However you are limited to 1.2M and I haven't tried it with an MP3.

Why do you want to do this?

I've done a project with the arduino Music shield. Thought I'd post the code and some of the sounds.

thanks