function play_mp3(p_track_id)
{
    _width  =   screen.width;
    _height =   screen.height;

    _x  =   screen.width/2 - 110;
    _y  =   screen.height/2 - 45;
    
    _win_mp3_preview =   window.open('mp3_player.php?track_id=' + p_track_id, 'win_mp3_preview', 'width=220, height=90, left=' + _x + ', top=' + _y +', status=no, resizable=no');
    _win_mp3_preview.focus();
}