load iframe without session inside administration

Question

I have inserted a button in a system plugin that will open an iframe in a modal window. The iframe content is administration login page. The issue is if I am logged in administration, the iframe also will be logged in. Is it possible to load the iframe without session?

<a href="http://www.example.com/administration" class="modal-button btn modal" style ="min-width: 194px;" rel="{handler: \'iframe\', size: {x:window.getSize().x-100, y: window.getSize().y-100}}" id="modalLink1"><span class="icon-screen"> </span> Preview</a>

Tried:

Add a preview parameter in the link:

<a href="http://www.example.com/administrator/index.php?preview=1" class="modal-button btn modal" style ="min-width: 194px;" rel="{size: {x:window.getSize().x-100, y: window.getSize().y-100}}"><span class="icon-screen"> </span> Preview</a>';

Set a cookie and unset session:

if ($input->get->get('preview', false) === '1') {
    $input->cookie->set('preview', '1', 0, $config->get('cookie_path'), $config->get('cookie_domain'), false, true);
    unset($_SESSION);
}

This could be a way of doing it?

Answer 1

To make it simple, if you only want to show an example, I would do this:

<?php JHTML::_('behavior.modal'); ?>

and

<a href="http://www.example.com/images/admin-login-example.png" 
class="modal-button btn modal" style ="min-width: 194px;" 
id="modalLink1"><span class="icon-screen"> </span> Preview</a>

where admin-login-example.png is a small screenshot of the login-page.

...so you don't have to worry about showing a live login form just as an example...