filter cat and tag

<ul><?php

query_posts('category_name=uncategorized');
	if (have_posts()) : while (have_posts()) : the_post();
        $posttags = get_the_tags();
		if ($posttags) {
			foreach($posttags as $tag) {
				$all_tags_arr[] = $tag->term_id; //USING JUST $tag MAKING $all_tags_arr A MULTI-DIMENSIONAL ARRAY, WHICH DOES WORK WITH array_unique
			}
		}
	endwhile; endif; wp_reset_query();

	$tags_arr = array_unique($all_tags_arr); //REMOVES DUPLICATES
	//echo '<pre>'.print_r($tags_arr, true).'</pre>'; //OUTPUT FINAL TAGS FROM CATEGORY

echo '<ul>';
foreach ($tags_arr as $tag) {
echo '<li><a href="' . get_tag_link($tag) . '">' . get_tag($tag)->name . '</a></li>';
}
echo '</ul>';

?></ul>