Hi Ureck, Have you tried directing your button with a target="parent" action to another script which then alters the two pages rather than just trying to do it with a button.
i.e:
<Form action="editpages.php" method="POST" target="parent">
<<YOUR FORM CODE>>
<input type="submit" value="Edit page">
--editpages.php--
<?
<<Your code to change content of first page>>
<<Your code to change content of second page>>
header("Location: <<The page you want them to see after they post>>");//this will redirect them to the page you want them to see after performing the alterations
?>
<HTML>
Refreshing.....
</HTML>