How to convert bitrate of audio files in javascript?

firstly, I have to say sorry for my bad English :)

Anyway, I'm going to develop a simple website that users can upload their audio files and play others' files. I planed to use Node.js, and HTML5 built-in audio tag to play the files. I have never used the audio tag, so I wondered if the tag really works fine, so today I lightly wrote a simple code and played a mp3 file and I got a problem, which is that the mp3 file wasn't be played using the tag. I realized the audio tag cannot play audio files above bitrate 128kbps. so now, I need a way of auto-converting from more than 128kbps to 128kbps, in javascript(using Node.js).

I've never used Node.js, so I never know how to do this. The things I want to know are that it is possible and it is easy.

Anyone give me how or where to find the solution please.

Thanks to read my bad-English question anyway.

Good luck :)