How to play song in Android - phonegap

A month ago I started working with phonegap, html5, css3 and jQtouch. I am working on an application and I need to play sound in the application. I have a serious problem with this task. First I've found out that I can play .mp3 files through phonegap using the new Media(...) function. I am not sure about .wav files, can I play those? Second I've found that files must be less than 30 sec, is this so? Third I can't find the right place for my sound files. My project structure is the following:

project
-- src
-- gen
-- assets
-- -- www
-- -- DANCE.mp3
-- -- jqtouch
-- -- -- (some folders and files)
-- -- phonegap.js
-- libs
-- res

I've tried placing the file in 'www' folder and creating a new one called 'audio'. None of this gave me what I wanted. I am using this code for executing the song:

function playStream() {
    mp3file = new Media("DANCE.mp3",
            function() {
                alert("playAudio():Audio Success");
            },
                function(err) {
                    alert(err);
            }
            );
          mp3file.play();
}

I use Android 2.1 Simulator and I've tried 2.2 as well without success. I hope I was clear enough. I am looking forward to hearing from you. Yours, Mihail Velikov