ng-click not working on submit button - angularjs

Question

I am learning how to use AngularJS, and I can't get a custom ng-click function to work. What I want to do is fire a $http.post request that contains data from my forms ($scope.email, $scope.username, $scope.password). So far I've tried only passing in email, but nothing happens when I click the submit button (there is no POST request fired, I am checking this with firebug). I tried passing it directly as $scope.email, or as a variable (as shown below).
I have a main page (index.html), that uses ng-view to load html using ngRoute. This the the route code:
.when('/register', {
templateUrl: 'views/register.html',
controller: 'RegisterCtrl'
})
Here is my register.html:
<div class="container">
<div class="col-xs-2 col-sm-3 col-md-4"></div>
<div class="col-xs-8 col-sm-6 col-md-4">
<h1>Sign Up:</h1>
<form>
<div class="form-group">
<label for="email">Email address:</label>
<input type="email" class="form-control" id="email" ng-model="email">
</div>
<div class="form-group">
<label for="username">Username:</label>
<input type="text" class="form-control" id="username" ng-model="username">
</div>
<div class="form-group">
<label for="pwd">Password:</label>
<input type="password" class="form-control" id="pwd" ng-model="password">
</div>
<button type="submit" class="btn btn-primary col-xs-5" ng-click="register">Sign up</button>
<div class="col-xs-2"></div>
<button class="btn btn-info col-xs-5">Go to log in</button>
</form>
</div>
</div>
and my controller:
'use strict';
angular.module('angularApp')
.controller('RegisterCtrl', function ($scope, $http) {
$scope.email = '';
$scope.username = '';
$scope.password = '';
$scope.register = function() {
// TODO ADD VALIDATION
var email = $scope.email;
var username = $scope.username;
var password = $scope.password;
// $http request
$http.post('http://localhost/PTC/API/new_user.php', email).
success(function(data) {
console.log(data);
}).
error(function(data) {
console.log(data);
});
};
});

Answer 1

it should have function () brackets to call function like ng-click="register()"
OR for more better way rather than using ng-click on form you could replace it with ng-submit directive
Markup
<form name="myForm" ng-click="register()">
...fields here..
<button type="submit" class="btn btn-primary col-xs-5">Sign up</button>
<div class="col-xs-2"></div>
<button class="btn btn-info col-xs-5">Go to log in</button>
</form>
Additionally you need to give form name to your form, so that you could get better controller over form validation.