Joomla 1.5 standart pop-ups (mootools + modal script)

You may see this pop-ups in Joomla back-end, when changing settings etc.

Add to head:

<?php
JHtml::_('behavior.modal', 'a.class_name');
?>

<script type="text/javascript">
window.addEvent('domready', function() {
    // Decorate the login windows to use a modal.

	$ES('a.class_name').each(function(a){
        a.setProperty('rel', '{size: {x: 900, y: 500}, ajaxOptions: {method: "get"}}');
        if (a.getProperty('href').contains('?')) {
            a.setProperty('href', a.getProperty('href')+'&tmpl=component');
        } else {
            a.setProperty('href', a.getProperty('href')+'?tmpl=component');
        }
    });
});
</script>

Then just add class attribute:

<a href="..." class="class_name">link text</a>

CSS-file located at:
/media/system/css/modal.css

JS-file located at:
/media/system/js/modal.js