[jQuery] Get value from hidden input and use it in string

[shapper]

Hello,

I am using JPlayer to play a sound on a page:
http://www.happyworm.com/jquery/jplayer/0.2.5/demo-04.htm

$(document).ready(function(){

   $("#jquery_jplayer").jPlayer({
      ready: function () {
          $("#trackname").text($("#track-01").text());
          $(this).setFile('http://www.miaowmusic.com/mp3/Miaow-05-The-
separation.mp3').play();
          demoInstanceInfo($(this), $("#jplayer_info"));
      }
   })
});

How can I change the setFile code line to:
  $(this).setFile('http://domain.com/asset/get/[id]').play();

Where [id] value should be taken from the following hidden input:
<input  TYPE="hidden" VALUE="2" NAME="Music">

Thank You,
Miguel