会话var没有被清除？

Question

page1.php中

$for = $_GET['name'];
session_start();
$_SESSION['new'] = $for;
session_write_close();
header('Location: http://newwebsite.com);

使page2.php

<?php
$new = '';
session_start();
$new = $_SESSION['new'];

?>

<script>  
    $(document).ready(function()
    {    
        <?php if($new != '') { ?>
        var banner = document.getElementById("A");
        var hiddenInput = document.getElementById("B");
        banner.innerHTML = <?php echo "'".$new."'" ?>;
        hiddenInput.value = <?php echo "'".$new."'" ?>;
        <?php }

        if(session_destroy())
        {
            unset($_SESSION['new']);
        }
        ?>
    });
</script>

我从page1.php获取数据但是它似乎永远不会被清除。

如果我这样做

print_r($_SESSION); 

导致空输出，但下次我从page1.php到另一个变量的页面时，它仍然显示旧的变量。我该怎么办？