Submitting the form in iframe and redirect the whole page

formsiframeredirect

i guess I have an easy question, I have not found the right answer yet thoguh.
I have an iframe in my page that comes from external domain. After submiting the form which is inside this iframe, I would like to redirect the whole page, not just content inside the iframe – i guess the right way to achieve might be via "target" attribute.
The sample html:

<html>
  <body>
    <h1>main page</h1>
    <iframe src="http://example.com">
      <form url="http://example.com/action">
        ...
      </form>
    </iframe>
  </body>
</html>

submitting the form should show me the result of submiting the POST request as a new page (not in the iframe)

Best Solution

I have put target='_parent' in the iframe but I haven't done this initially in the form element. After adding target='_parent' attribute to form it started to work as expected.