How to click a button and focus on another input in angularjs?

I don't know how to focus on an input when clicking on a button in angularjs.

I create a simple demo which can't work here: http://plnkr.co/edit/NS0jJE9ttakNm8nc6QkZ?p=preview

This is the main code:

app.controller('MainCtrl', function($scope, $element) {
  $scope.name = 'World';
  $scope.myfocus = function(){
    $element.find("#myinput").???? // what to do here?
  }
});