title: get unchecked box
body: <p>I have a form of a table with 'checkbox':</p>
  
  <pre><code>  out.print("&lt;table&gt;&lt;tr&gt;");
    String box_user = null;
    out.print("&lt;td&gt;");
    box_user = "&lt;input name = 'check' value=r" + id + " type='checkbox'&gt;";
    out.print(box_user);
    out.print("&lt;/td&gt;");
    out.print("&lt;/tr&gt;&lt;/table&gt;");
  </code></pre>
  
  <p>I got all the checked box by:</p>
  
  <pre><code>String[] str;
  str = request.getParameterValues("check");
  </code></pre>
  
  <p>now, I want to get all the unchecked box. how can I get it?</p>