title: Local Storage communication for 2 windows
body: <p>I created a small project where I click a Button which opens a new window. This window is requesting information from a server.</p>
  
  <p>The window should now pass the information back to mainpage where the Button is placed.</p>
  
  <p>I tried to work with localStorage and this is what I got until now:</p>
  
  <p>Sender:</p>
  
  <pre><code>var fbKey = "test";
  
  localStorage.fb_auth_key = fbKey;
  
  alert(localStorage.fb_auth_key);
  </code></pre>
  
  <p>Receiver:</p>
  
  <pre><code>document.getElementById('output').textContent = "" + localStorage.fb_auth_key;
  </code></pre>
  
  <p>The Receiver is refreshing this all the time, but I always get "undefined" - the alert in the sender has the right result.</p>
  
  <p>Thanks for helping.</p>