loginUser(username: string, password:string): Observable<IUserLoginInformation> {

        return this.http.post(this._globalConstants.loginUrl,
            JSON.stringify({ username: username, password: password }))
            .map((res: Response) => res.json());
    }

login(){
       this._loginService.loginUser(this.username,this.password)
           .subscribe((data) => {
          this._userService.setUser(data);
       });
    }