php datagrid delete page problem

Hello i am working with datagrid . i have done with pagination and edit now i am getting problem with delete . in pagination it automatically make pages in one page . here is the code from where i am calling

$deletetUrl = "admin.php?page=delete_user&id=".$data["user_id"]."&pageid=".$pageNumber." ";             
$delete = "<a href='".$deletetUrl."'><img src='".$assets."edit-delete.png' alt='Delete' title='Delete' border='0' height='16' width='16'></a>";

its going to this page

        <?php           
            echo $query  = "Delete from user where user_id=$_GET[id]";
            $result = mysql_query($query);


            ?>

        <script type="text/javascript">
        window.location="admin.php?page=view_user&开发者_StackOverflow社区;pageid=<?php echo urlencode($_GET[pageid]); ?>"
        </script>

it delete perfectly and with this javascript function it goes back it goes to page 1 of the records although i have delete from another page . please let me how can i go to same page from where i have deleted the record in this case or anybody can suggest small ajax function which can come up with the soluction

    <?php         
    /* You should sanitize the $_GET['id'] input & restrict access to this page as
    your vulnerable to sql injection as posting ?id=1 would most likely delete your admin user
    */
    $query  = "Delete from user where user_id=$_GET[id]";
    $result = mysql_query($query);
    header('Location: admin.php?pageid='.$_REQUEST['pageid']);

    ?>