title: How do I programmatically refresh a browser
body: <p>I have three computers; <code>Server</code>, <code>Client</code> and <code>Viewer</code>. I am in control of the server and the viewer.
  <img src="https://i.stack.imgur.com/rkC9T.png" alt="workflow"></p>
  
  <ol>
  <li>The user on the <code>Client</code> connects to the <code>Server</code> and is presented with a webpage.</li>
  <li>Through a php script the user uploads an image.</li>
  <li>The image is imbedded in some html.</li>
  <li>The <code>Viewer</code> is a computer totally without user interaction - there is no keyboard. The <code>Viewer</code> is always at all time running a web browser, displaying the picture page.</li>
  </ol>
  
  <p>My problem now is that even though the picture changes on the server disk, the webpage is not updated. How do I refresh the web browser on the viewer, or part of the webpage?</p>
  
  <p>I know html, css, javascript, php and ajax, but apparently not well enough.</p>