layer about jquery ajax calls

core.js

function go_ajax(url, method, data, success_func, extra_dict) {
      if ($.type(data) === "function") {
          var success_func_holder = success_func;
          success_func = data;
          extra_dict = success_func_holder;
          data = undefined;
      }
    $.ajax({
        url: url,
        type: method,
        data: data ? JSON.stringify(data) : null,
        contentType: "application/json;charset=UTF-8",

        success: success_func,
        complete: extra_dict && extra_dict.complete ? extra_dict.complete : null,
        error: extra_dict && extra_dict.error ? extra_dict.error : function ($ajax) {
            if ($ajax.statusCode === 500){
                pop('Damn the server, something went wrong with it.', 'error');
            } else if ($ajax.statusCode === 400){
                pop('Something went wrong!')
            } else {
               pop('An error occurred', 'error')
            }
        },
        context: extra_dict && extra_dict.context ? extra_dict.context : null

    });
}

function bring_json(url, data, func) {
    $.getJSON(url, data, func);
}