Redirect form out of modal window after submit
I would suggest using #ajax to submit the form and then allow the response to close the modal and go somewhere else. For example, here's a submit button that runs a function on click instead of submitting the form and reloading the page:

$form['submit'] = array(
  '#prefix' =&gt; '&lt;div id="super-cool-wrapper"&gt;&lt;/div&gt;',
  '#type' =&gt; 'button',
  '#value' =&gt; 'Submit',
  '#ajax' =&gt; array(
    'callback' =&gt; 'my_super_cool_ajax_callback',
    'wrapper' =&gt; 'super-cool-wrapper',
    'method' =&gt; 'replace',
  ),
);


And then in your callback function:

function my_super_cool_ajax_callback($form, $form_state) {
  // Do what you normally would with the form submission.
  return '&lt;script type="text/javascript"&gt;
    parent.window.location="some/where";
  &lt;/script&gt;';
}


Now you can process the form as needed and return a response that simply redirects the user.