title: How to set focus to the div when button click in angular 2?
body: <p>I want to set focus to the <code>div</code> which is top of the page when clicking the button. It means it validates when click the button, if validation fails, it need to focus the top of the page, where the validation error shows.</p>
  <p>So how to get the focus the top of the page div. And form is in <code>modal-dialog</code>.</p>