richiedere registrazione nella productID

[pieroflash]

ciao ragazzi mi servirebbe un aiuto urgente se possibile ovviamente nel ecommerce che sto creando sulla sinistra c'e' un menu con la sigla dei prodotto es: maglietta e si apre la pagina delle magliette(productID) credo, vorrei che nella pagina index appunto quando clico su una di queste scritte a sinistra mi chiedesse la registrazione al sito .

io le pagini protette le tengo cosi:

<?
session_start();
if(!session_is_registered(username)){
header("location: regist/login.php");
}
?>

questo e il codice dell index.php :

<?php

    //includo i files
    include("./cfg/connect.inc.php");
    include("./includes/database/mysql.php");
    include("./cfg/general.inc.php");
    include("./cfg/appearence.inc.php");
    include("./cfg/functions.php");
    include("./cfg/category_functions.php");
    include("./cfg/language_list.php");
    
    @session_start();

    ini_set("display_errors", "1");

    //init Smarty
    require 'smarty/smarty.class.php'; 
    $smarty = new Smarty; //core smarty object
    $smarty_mail = new Smarty; //for e-mails

    //select a new language?
    if (isset($_POST["new_language"]))
    {
        $_SESSION["current_language"] = $_POST["new_language"];
    }

    //current language session variable
    if (!isset($_SESSION["current_language"]) ||
        $_SESSION["current_language"] < 0 || $_SESSION["current_language"] > count($lang_list))
            $_SESSION["current_language"] = 0; //set default language
    //include a language file
    if (isset($lang_list[$_SESSION["current_language"]]) && file_exists("./languages/".$lang_list[$_SESSION["current_language"]]->filename))
        include("./languages/".$lang_list[$_SESSION["current_language"]]->filename); //include current language file
    else
    {
        die("<font color=red>[b]ERROR: Couldn't find language file![/b]</font>");
    }

    //connessione
    db_connect(DB_HOST,DB_USER,DB_PASS) or die (db_error());
    db_select_db(DB_NAME) or die (db_error());

    //get currency ISO 3 code
    $currency_iso_3 = (defined('CONF_CURRENCY_ISO3')) ? CONF_CURRENCY_ISO3 : "USD" ;
    $smarty->assign("currency_iso_3", $currency_iso_3);

    //load all categories to array $cats to avoid multiple DB queries (frequently used in future - but not always!)
    $cats = array();
    $i=0;
    $q = db_query("SELECT categoryID, name, parent, products_count, description, picture FROM ".CATEGORIES_TABLE." where categoryID<>0 ORDER BY name") or die (db_error());    
    while ($row = db_fetch_row($q))
    {
        $cats[$i++] = $row;
    }

    //set $categoryID
    if (isset($_GET["categoryID"]) || isset($_POST["categoryID"]))
        $categoryID = isset($_GET["categoryID"]) ? $_GET["categoryID"] : $_POST["categoryID"];
    else $categoryID = 0;

    $categoryID = (int)$categoryID;

    //$productID
    if (!isset($_GET["productID"]))
    {
        if (isset($_POST["productID"]))
        {
            $productID = (int)$_POST["productID"];
        }
    }
    else
    {
        $productID = (int)$_GET["productID"];
    }

    //and different vars...
    if (isset($_GET["register"]) || isset($_POST["register"]))
        $register = isset($_GET["register"]) ? $_GET["register"] : $_POST["register"];
    if (isset($_GET["update_details"]) || isset($_POST["update_details"]))
        $update_details = isset($_GET["update_details"]) ? $_GET["update_details"] : $_POST["update_details"];
    if (isset($_GET["order"]) || isset($_POST["order"]))
        $order = isset($_GET["order"]) ? $_GET["order"] : $_POST["order"];
    if (isset($_GET["check_order"]) || isset($_POST["check_order"]))
        $check_order = isset($_GET["check_order"]) ? $_GET["check_order"] : $_POST["check_order"];
    if (isset($_GET["proceed_ordering"]) || isset($_POST["proceed_ordering"]))
        $proceed_ordering = isset($_GET["proceed_ordering"]) ? $_GET["proceed_ordering"] : $_POST["proceed_ordering"];

    if (!isset($_SESSION["vote_completed"])) $_SESSION["vote_completed"] = array();

    //checking for proper $offset init
    $offset = isset($_GET["offset"]) ? $_GET["offset"] : 0;
    if ($offset<0 || $offset % CONF_PRODUCTS_PER_PAGE) $offset = 0;




    // -------------SET SMARTY VARS AND INCLUDE SOURCE FILES------------//

    if (isset($productID)) //to rollout categories navigation table
    {
        $q = db_query("SELECT categoryID FROM ".PRODUCTS_TABLE." WHERE productID='$productID'") or die (db_error());
        $r = db_fetch_row($q);
        if ($r) $categoryID = $r[0];
    }

    //set Smarty include files dir
    $smarty->template_dir = $lang_list[$_SESSION["current_language"]]->template_path;
    $smarty_mail->template_dir = $lang_list[$_SESSION["current_language"]]->template_path."/mail";

    //assign core Smarty variables

    $smarty->assign("lang_list", $lang_list);
    $smarty->assign("lang_list_count", count($lang_list));

    if (isset($_SESSION["current_language"])) $smarty->assign("current_language", $_SESSION["current_language"]);
    // - following vars are used as hidden in the customer survey form
    $smarty->assign("categoryID", $categoryID);
    if (isset($productID)) $smarty->assign("productID", $productID);
    if (isset($_GET["currency"])) $smarty->assign("currency", $_GET["currency"]);
    if (isset($_GET["user_details"])) $smarty->assign("user_details", $_GET["user_details"]);
    if (isset($_GET["aux_page"])) $smarty->assign("aux_page", $_GET["aux_page"]);
    if (isset($_GET["show_price"])) $smarty->assign("show_price", $_GET["show_price"]);
    if (isset($_GET["adv_search"])) $smarty->assign("adv_search", $_GET["adv_search"]);
    if (isset($_GET["searchstring"])) $smarty->assign("searchstring", $_GET["searchstring"]);
    if (isset($register)) $smarty->assign("register", $register);
    if (isset($order)) $smarty->assign("order", $order);
    if (isset($check_order)) $smarty->assign("check_order", $check_order);

    //set defualt main_content template to homepage
    $smarty->assign("main_content_template", "home.tpl.html");
    // includes all .php files from includes/ dir
    $includes_dir = opendir("./includes");
    while ( ($inc_file = readdir($includes_dir)) != false )
        if (strstr($inc_file,".php"))
        {
            include("./includes/$inc_file");
        }

    // output:

    //security warnings!
    if (file_exists("./install.php"))
    {
        echo "<center>".WARNING_DELETE_INSTALL_PHP."</center>";
    }
    if (file_exists("./forgot_password.php"))
    {
        echo "<center>".WARNING_DELETE_FORGOTPW_PHP."</center>";
    }

    if (!is_writable("./products_pictures") || !is_writable("./templates_c"))
    {
        echo "<center>".WARNING_WRONG_CHMOD."</center>";
    }

    //show administrative mode link if logged in as administrator
    include("./checklogin.php");
    if (isset($_SESSION["log"]) && isset($_SESSION["pass"]))
        echo "
<center><a href=\"admin.php\"><font color=red>".ADMINISTRATE_LINK."</font></a></center>

";

    //show Smarty output
    $smarty->display($lang_list[$_SESSION["current_language"]]->template_path."index.tpl.html"); 

?>

come posso risolvere in modo che quando cliccano la categoria a sinistra richiede la registrazione? grazie help help