Hi,
To fix the "add to cart" button issue, open this PHP file:
/templates/flexible_lightmart/layouts/template.php
and include these PHP lines to very bottom (after the </html> line ):
JHTML::stylesheet("facebox.css","components/com_virtuemart/assets/css/");
JHTML::script("facebox.js", "components/com_virtuemart/assets/js/");
$document = JFactory::getDocument();
$document->addScriptDeclaration("
jQuery(document).ready(function() {
jQuery('a[rel*=facebox]').facebox()
});
");
it should fix the add to cart button issue.