title: Retrieve POST checkbox data from form if they exist
body: <p>Hello knowledgeable people. I am having trouble retrieving checkbox data from form. I have a site in which user can add checkboxes themselves, so I am writing them out like this:</p>
  
  <pre><code>&lt;table style="padding:10px;"&gt;
              &lt;?php
  
              $query_boolean = $DB-&gt;prepare("SELECT * FROM moduls WHERE type='boolean'") or die(mysql_error());
              $query_boolean-&gt;execute();
              while (($row = $query_boolean-&gt;fetch()) != false)
                  {
  
                      ?&gt;
                      &lt;tr&gt;
                          &lt;td&gt;
                          &lt;?php echo $row-&gt;name ?&gt;:
                          &lt;/td&gt;
                          &lt;td&gt;
                              &lt;?php
                              $s = "";
  
                              $s .= sprintf('&lt;input type="checkbox" class="textbox" name="boolean_%s" value="yes"&gt;%s', $row-&gt;id, Yes);
                              $s .= sprintf('&lt;input type="checkbox" class="textbox" name="boolean_%s" value="no"&gt;%s', $row-&gt;id, No);
  
                              echo $s;
                              ?&gt;
                          &lt;/td&gt;
                      &lt;/tr&gt;
                      &lt;?php
  
                      }
                      ?&gt;
  
  
              &lt;/table&gt;
  </code></pre>
  
  <p>Now I have an advanced search in which I have to chech through every checkbox to see what has been selected (ether none, Yes, No, or both). How can I get the info from every checkbox in variables? Thank you so much!</p>