Thi child page's code should look something like this, you need to call the JS function after the data is posted.

Code: PHP
if($_SERVER['REQUEST_METHOD'] == 'GET')
    {
?>
    <form name=sub method=post>
    <input type=text name=ss>
    <input type=text name=cc>
    <input type=submit value=run>
    </form>
<?
    }
    else
    {
       
$ss=$_POST['ss'];
$cc=$_POST['cc'];
$array=array($ss,$cc);
?>
        <script language="JavaScript">
        function jss()
        {
        window.opener.document.add.cus.value="<?php echo base64_encode(serialize($array));?>";
        }
        jss();
        </script>

        <?
    }