block view and Facet API

Hello,

In my website I used Apache Solr and facet api to display facets search blocks,
I created a custom module that show users a block that save trough a form the current request_uri,

but now I want to add to this block another content that show me the active filters that the user have shosen.
Here my block_view code :

<?php
function sf_block_view($delta = '') {
	$block = array();
	switch($delta) {
		case 'sf':
			$block['subject'] = t('Save this filter result');
			$block['content'] = drupal_get_form('sf_form');
		break;
}
	return $block;
}
?>

So how can I first add another content to the $block['content'] variable
and also how can I list the active filters chosen by user

Thanks in advance