[jQuery] IF and NULL. Please, could someone help me out?

[shapper]

Hello,

I have the following:

  $("#JPlayer").jPlayer({
    ready: function() {
      $(this).setFile($('#MusicPath').attr("value")).play();
    },
    swfPath: $('#JPlayerPath').attr("value")
  });

I would like the play the file:
$(this).setFile($('#MusicPath').attr("value")).play();

Only if ( $.cookies.get("AlliedSkills.Player") = "Play )

If ($.cookies.get("AlliedSkills.Player") is null then do not play and
set only the file:
$(this).setFile($('#MusicPath').attr("value"));

Could someone please help me in doing this?

Thanks,
Miguel