title: auto reload (auto refresh) html page when cookie change
body: <p>how can html page auto reload when the cookie change?       </p>
  
  <p>I have this code in my main html page :      </p>
  
  <pre><code> body onload="set_style_from_cookie()" 
  </code></pre>
  
  <p>when I change the style for the main html page from another page , how can the main page detect this change and auto reload? </p>