get_post order

I’m using a widget that shows the categories and posts on the sidebar as a menu.

The problem is that i need a reversed order (older posts first).

This is the part of the code that responsible of getting/displaying the posts:

// Get array of post info.
	$cat_posts = get_posts('numberposts='.$num.'&category='.$cat_id);

	echo $before_widget;
	echo $before_title;

	if( $title_link ) {
		echo '<a href="' . get_category_link($cat_id) . '">' . $title . '</a>';
	} else {
		echo $title;
	}

	echo $after_title;
	echo '<ul>';
	foreach($cat_posts as $post) {
		setup_postdata($post);
		echo '<li class="cat-posts-item-' . $post->ID . '"><a href="' . get_permalink($post) . '">' . $post->post_title . '</a>';
		if( $excerpt ) {
			echo '<br />';
			if ($post->post_excerpt!=NULL)
				echo $post->post_excerpt;
			else
				the_excerpt();
		}
		echo '</li>';
	}
	echo '</ul>';
	echo $after_widget;

How can i reverse the order ?

Thanks,
E-A.