function Login(username, password, callback) {
        var user = {username:username, password:password};
        var data = JSON.stringify(user);
        $http.post('http://127.0.0.1:8000/socialnet/auth/',data)
            .success(function (response) {
                callback(response);
            })
            .error(function(response){
                alert("some error happened");
            });
}

function login() {
        vm.dataLoading = true;
        AuthenticationService.Login(vm.username, vm.password, function (response) {
            AuthenticationService.SetCredentials(vm.username, vm.password,response.author);
        });
};