How to pass or fetch data from AngularJS to Aspx using WebMethod?

I have to fetch a string from aspx to angularJS and display it. But I am not getting any response or it might be AngularJS is not triggering the method. Here is my Angular Controller

controller('ReadTextController', function ($scope, $http, $location) {

        $scope.showData = function () {
            $http.post('KeyPhraseGroup.aspx/GetEmployees', { data: {} })  
.success(function (data, status, headers, config) {  
    $scope.result = data.d;  
})  
.error(function (data, status, headers, config) {  
    $scope.status = status;  
});  
}  
});

And here is my aspxmethod

[WebMethod]
    public static string GetEmployees()
    {
        return "Hello World";
    }

I am triggering the showData() method of the AngularJS controller in my html page but not getting the string fetched.

Changed Explanation

I am getting value as undefined