title: Form submit not working when using magento secure url for action
body: <p>I have a from that when submit runs a little php to export data to a csv.  The php looks like : </p>
  
  <pre><code>$out = '';
  if (isset($_POST['csv_hdr'])) {
  $out .= $_POST['csv_hdr'];
  $out .= "\n";
  }
  
  if (isset($_POST['csv_text'])) {
  $out .= $_POST['csv_text'];
  }
  
  $filename = "z_".date("Y-n-d",time());
  header("Content-type: application/vnd.ms-excel");
  header("Content-disposition: csv" . date("Y-n-d") . ".csv");
  header("Content-disposition: filename=".$filename.".csv");
  print $out;
  exit;
  </code></pre>
  
  <p>This works fine if I do a normal path to the php file like : </p>
  
  <pre><code>&lt;form name="export"  action="http://website.com/getcsv.php"  method="post"&gt; 
  </code></pre>
  
  <p>I am trying to move this php function into a controller now and call it that way.  I am working on a magento admin module so I have to pass the url with the security key.  So I move that function into an action in the controller :</p>
  
  <pre><code>public function getcsvAction(){
      $out = '';
      ...
  }
  </code></pre>
  
  <p>Then I am able to get the url with something like :</p>
  
  <pre><code>&lt;?php echo Mage::helper("adminhtml")-&gt;getUrl("module/index/getcsv/");?&gt;
  </code></pre>
  
  <p>This gives me a link with the key like :</p>
  
  <pre><code>http://website.com/module/index/getcsv/key/7431c859914c40d3f66dfcd1530813b3/
  </code></pre>
  
  <p>If I paste that link into the browser it executes the php fine.  However when I replace it in my form action it no longer works and just does a redirect to the dashboard.  I can not see any errors output and I am not sure what is happening.  Any ideas on how to get this POST to work using a secure path as the action?</p>