Callback-Magic.js

addWorksListener($('.commodity_works'));

function addWorksListener (obj) {
                obj.change(function () {
                  if ( $('.commodity_works').size() == 1 ) {
                    var id = $('#commodity_works').val();
                    pasteDataFromWork(id);
                  } else {
                    $('.commodity_works').each( function() {
                      $.getJSON( 'http://fileservr.technoload.abc:3000/works/' + $(this).val() + '/filetype.json', function (data,result) {
                        if ( result == 'success') {
                          if ( type == '' ) {
                            type = data.filetype.title;
                          }
                          if ( type != data.filetype.title ) {
                            type = false ;
                          }
                          type_check_iterations = type_check_iterations + 1;
                          if ( type_check_iterations == $('.commodity_works').length ) {
                            if ( (type == '') || (type == false ) ) {
                              alert ('#{ t("fileservr.commodities.new.noConversionOfDifferentTypes") }'); 
                            } else {
                              switch (type) {
                                case 'audio':
                                  $('#resolution').html('#{ escape_javascript( render :partial => "resolutions", :locals => { :type => 'audio' } ) }');
                                  break;
                                case 'video':
                                  $('#resolution').html('#{ escape_javascript( render :partial => "resolutions", :locals => { :type => 'video' } ) }');
                                  break;
                                case 'image':
                                  $('#resolution').html('yeahaw!');
                                  break;
                              }
                            }
                          type = '';
                          changePreviews();
                          }
                        }
                        });
                     });
                    }
                });
              }