Oh right you wanted to carry it over to the popup which is easily done through GET methods.
code:
<form action='' method="post" onSubmit="window.open('script.php?submit=' + this.elements['submit'].value + '&name=' + this.elements['name'].value, 'WindowName', 'height=100,width=100'); setTimeout(window.location, 2000); return false;">
    <input type="text" name="name" /> <!-- just testing -->
    <input type="submit" name="submit" value="Submit" />
</form>
And I tested this in a file called 
script.php:
code:
 <?php
 $tf = (isset($_GET['submit'])) ? "True" : "False";
 $name = (isset($_GET['name'])) ? $_GET['name'] : "False";
 
 echo $tf;
 echo "<br />";
 echo $name;
 ?>
Which outputted:
    True
    Boo 
(this being what I put in the name input).
Only downside is that you have to put all of the 
names of the input boxes that you want to send over to 
script.php in the window.open() function.