Need help to create cutom scrollbar

hi, i can't get my scroll bar to appear and work, below is my coding for it.

Thanks

yepnope({nope:[ 'jquery.mCustomScrollbar.css',

                             'jquery.mCustomScrollbar.js',

                                                      'jquery.mousewheel.min.js',

                                                        'jquery-ui-1.8.21.custom.min.js',

                                                        'jquery-1.8.3.min.js'

                                                       ],complete: init});

         function init (){

                              sym.$("Group").mCustomScrollbar({

                                        scrollInertia:850,

                                        scrollEasing:"easeOutCirc",

                                        scrollButtons:{

                                        enable:true

                                                            }

                                        });

                              }