Passing variables between PHP pages

I am trying to pass a variable between two PHP pages. Here's the scoop: to get to the first PHP page, I email a URL to a user that gives the search criteria (www.whatever.com/pagea.php?userid=2) This works just fine. pagea.php has a select statement to pull a record from my MySQL database based on the userid in the URL. This displays just fine. pagea.php has a two radio buttons at the bottom of it, one to "Accept" and one to "Reject". Below this is the "submit" button. pagea.php is configured as "form method=post" with the "action=pageb.php". pageb.php does not get passed the userid variable that was passed in the URL to pagea.php. How can I pass that same variable to pageb.php when the user clicks the "submit" button on pageb.php? In pagea.php, after the select query and the fetch_array statement, I assign a variable name to the results of the userid column ("$wow = $result[userid]). The $wow variable does not get passed to pageb.php either. Any help is appreciated. Michael Conley