Shortcodes on pages

Hi,

I’m developing a plugin for wordpress and I’m trying to use shortcodes to add content to posts and pages. I added a shortcode handler for it like this:

function foobar_shortcode($attr) {
ob_start();
include($pluginpath . ‘foobar.php’);
$ret = ob_get_contents();
ob_end_clean();
return $ret;
}
add_action(‘foobar’, ‘foobar_shortcode’);

Now [foobar] works on posts, but not on pages. So how can I get shortcodes to work also on pages?