title: Get the current browser window center
body: <p>How do I get the browser window height so I can find the center position?</p>
  
  <p>I only need the window height, not the web page height.</p>
  
  <p>I tried <code>$(window).height() / 2</code> but it only works if the browser has focus from the top of the page. If I scroll down I get the wrong center.</p>