How can redirect another page searching zip code value get successful ?

I am find value zip code is available or not try http://ift.tt/1T32Em7 this plug in when get zip code is available then few second after how can redirect anoter page ?

note: in this code header() function is not work.

protected function handleRequests()

{
    global $wpdb;

    $task = isset($_REQUEST['task']) ? $_REQUEST['task'] : null;
    if( !$task )
        return false;

    if( $task == 'wc_check_delivery' || $task == 'wc_check_delivery2'  )
    {
        $ops = get_option('wc_cd_settings', array());
        if( !is_array($ops) )
            $ops = array();

        $code = trim($_GET['code']);
        $query = "SELECT * FROM {$wpdb->prefix}wc_delivery_codes WHERE code = '$code' LIMIT 1";
        $row = $wpdb->get_row($query);

        if( !$row )
        {
            $query = "SELECT * FROM {$wpdb->prefix}wc_delivery_codes WHERE code LIKE '%*' AND SUBSTRING(code,1,LENGTH(code-1)) = SUBSTRING('$code',1,LENGTH(code-1))  AND LENGTH(code) <= LENGTH('$code') LIMIT 1";

            $row = $wpdb->get_row($query);
            if( !$row )
            {
                $query = "SELECT * FROM {$wpdb->prefix}wc_delivery_codes WHERE code LIKE '%?' AND SUBSTRING(code,1,LENGTH(code-1)) = SUBSTRING('$code',1,LENGTH(code-1)) AND LENGTH(code)= LENGTH('$code') LIMIT 1";

                // $query = "SELECT * FROM {$wpdb->prefix}wc_delivery_codes WHERE code LIKE '$code%' AND   code LIKE '%*' LIMIT 1";
                $row = $wpdb->get_row($query);
                if( !$row )
                {
                    if($task=="wc_check_delivery2")
                        die('false');
                    $msg = (isset($ops['error_msg']) && !empty($ops['error_msg'])) ? $ops['error_msg'] : __('Oops! This Zip/Pin code is not found');
                    die($msg);
                }
            }
        }
        //print_r($row);

        $time = time();
        $d_time = $time + ($this->_day_seconds * $row->days);
        $msg = sprintf(__('Estimated Delivery in %d days (by %d %s, %d)'), $row->days, date('d', $d_time), date('M', $d_time), date('Y', $d_time)) . '<br/>';


        if( !empty($row->note) )
                $msg .= sprintf(__('Note: %s'), $row->note) . '<br/>';

        die($msg);


    }
}

via Chebli Mohamed