in log in form ng-submit or ng-click are not working

#login.html

<form method="post" role="form" id="login" class="login-form fade-in-effect">

                <div class="login-header">
                    <a href="#/app/dashboard-variant-1" class="logo">
                        <img src="assets/images/[email protected]" alt="" width="80" />
                        <span>log in</span>
                    </a>

                    <p>Dear user, log in to access the admin area!</p>
                </div>

                <div class="form-group">
                    <label class="control-label" for="username">Username</label>
                    <input type="text" class="form-control input-dark" name="username" id="username" autocomplete="off" ng-model="LoginCtrl.inputData.username" />
                </div>

                <div class="form-group">
                    <label class="control-label" for="passwd">Password</label>
                    <input type="password" class="form-control input-dark" name="passwd" id="passwd" autocomplete="off" ng-model="LoginCtrl.inputData.password" />
                </div>
                 <div class="alert alert-danger" ng-show="errorMsg">
                        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">
                        ×</button>
                        <span class="glyphicon glyphicon-hand-right"></span>  {{errorMsg}}
                  </div>
                <div class="form-group">
                    <button type="submit" class="btn btn-dark  btn-block text-left" ng-click="LoginCtrl.postForm(this.form)">
                        <i class="fa-lock"></i>
                        Log In
                    </button>
                </div>

                <div class="login-footer">
                    <a href="">Forgot your password?</a>

                    <div class="info-links">
                        <a href="">ToS</a> -
                        <a href="">Privacy Policy</a>
                    </div>

                </div>

            </form>

#controller

controller('LoginCtrl',function($scope, $rootScope,$http)
    {
        $rootScope.isLoginPage        = true;
        $rootScope.isLightLoginPage   = false;
        $rootScope.isLockscreenPage   = false;
        $rootScope.isMainPage         = false;

        this.postForm = function() {
            
                var encodedString = 'username=' +
                    encodeURIComponent(this.inputData.username) +
                    '&password=' +
                    encodeURIComponent(this.inputData.password);
 
                $http({
                    method: 'POST',
                    url: 'userauth.php',
                    data: encodedString,
   
                })
                
                .success(function(data) {
                        console.log(data);
                        if ( data.trim() === 'correct') {
                            window.location.hash = '#/app/dashboard-variant-1';
                        } else {
                            $scope.errorMsg = "Username and password do not match.";
                        }
                })             }

    })

#userauth.php

<?php

    $username = $_POST['username'];
    $password = $_POST['password'];

    if ($username == "supriyo" && $password == "abc@123") {

        echo "correct";
    }
    else{

        echo "wrong";
    }
 ?>

this methos are not working