http post request with response in angular2 Nativescript

Question

i am new to angular2 native script programming.. i need to post data to a particular url from my app. when i try to post data then get a message on console Response with status: 200 for URL: null. whats the meaning of this message.? and what should i do for successfull post request..?

//my code

                 let headers = new Headers({ "Content-Type": "application/json" });
                 let options = new RequestOptions({ headers: headers });
                 let body = 
                 {
                    "firstName": "boby",
                    "lastName": "samuels",
                    "Location": "UK"

                 };
                 this.http.post("http://example.com", JSON.stringify(body), options)
                 .subscribe(result => 
                     {
                        console.log("response : "+result);
                     }, error => 
                     {
                     console.dir(error);
                     });

please help me out.