code: function ajaxRequest(opt, callback){
          if(!ajaxObj) ajaxObj = new ajaxClass();
          if(!opt.url) callback("URL cannot be empty");
          else if(!opt.type) callback("Type cannot be empty");
          else ajaxObj.init(opt.url, opt.type, opt.contentType, opt.headers, opt.data, callback);
      }
docs: class calls