title: Getting a Input type="image" value from a request.getParameter()
body: <p>Inside of my html, I have form that post back to my Servlet. I would like to get the value of my input type ="image" but instead I am receiving a null value.</p>
  
  <p>My form:</p>
  
  <pre><code> &lt;form action="HomeController" method="post"&gt;
     &lt;button type="submit" name="s4" value="someValue"&gt;
       &lt;img src="s4.jpg" alt="phonestuff"&gt;
     &lt;/button&gt;
     &lt;input type="hidden" name="s4price" value="800"&gt;  
   &lt;/form&gt;
  </code></pre>
  
  <p>my Servlet post:</p>
  
  <pre><code>double s4price = Double.parseDouble(request.getParameter("s4price"));
  String s4 = request.getParameter("s4");
  System.out.println(s4price);
  System.out.println(s4);
  </code></pre>
  
  <p>My output:</p>
  
  <pre><code>800.0
  null
  </code></pre>
  
  <p>Expected output:</p>
  
  <pre><code>800.0
  Note4
  </code></pre>