title: How to use PHP to restore page with content
body: <p>I am trying to build a web app like this using php, it has two pages:
  <br>
  <strong>select.php</strong> has some radio buttons in a html form for users to choose. and there is a submit button post the form to a confirmation page.</p>
  
  <p><strong>confirm.php</strong> echos the summery from previous page and there is a "back" button allow users to change their selections in the previous page. </p>
  
  <p>In this point, when I hit the "back" button and previous page restored, I would like all my previous selections displayed. (more clearly, if I chose a radio button and submit in select.php, I want the radio button still being chose after I go back to select page by hitting "back" button from confirm.php page.)</p>
  
  <p>Please give me some idea about how to do this kind of restore page thing.</p>