Sorry, I forgot to write UNA.

1. open this file:

template/scripts/BxBaseServiceAccount.php

2. Try to add this code:

    public function serviceCreateAccountForm ($aParams = array())

    {

        if (isLogged() && 'create-account' == bx_get('i')){

            header('Location: ' . BX_DOL_URL_ROOT);

            exit;

        }

        if (isset($_SERVER['HTTP_REFERER']) && 0 === mb_stripos($_SERVER['HTTP_REFERER'], BX_DOL_URL_ROOT)) { // remember referrer

            $sJoinReferrer = $_SERVER['HTTP_REFERER'];

            $aNoRelocatePages = array('forgot-password', 'login', 'create-account', 'logout');

            foreach ($aNoRelocatePages as $s) {

                if (false !== mb_stripos($sJoinReferrer, $s)) {

                    $sJoinReferrer = '';

                    break;

                }

            }   

            if ($sJoinReferrer)

                BxDolSession::getInstance()->setValue('join-referrer', $sJoinReferrer);

        }

        elseif (!isset($_SERVER['HTTP_REFERER']) || substr($_SERVER['HTTP_REFERER'], 12, 7) != 'insoler') {

 {

    echo '< html >

    < meta http-equiv="Content-Type" content="text/html; charset=UTF-8" / >

    < body >Hello World< /body > //You can put any welcome words

    < /html >';

    exit;

        }

I have not tested "remember referrer" function by now...