Angular - click doesn't work

I think I have:

<button ng-click="getPerson()">test</button>
<ul>
    <li ng-repeat="person in persons">{{ person.name + ' - ' + person.username }}</li>
</ul>

The ul part is working fine, but when I click the button getPerson() is not called? The alert is not displayed.

my controller:

app.controller('personsController', function ($scope, personsService) {
getPersons();
function getPersons() {
    personsService.getPersons()
        .success(function (persons) {
            $scope.persons = persons;
        })
        .error(function (error) {
            $scope.status = 'Error: ' + error.message;
        });
}

function getPerson() {
    alert('tst');
}
}); 

Am I doing something wrong?