Wordpress query_post question

Hello forums,

Im kinda stuck with my function. Im tryng to query post on certain categies but it just displays the lates entries

function footLink($cat){
query_posts('cat=$cat'); 
if ( have_posts() ) : while ( have_posts() ) : the_post();
?>
<li><a href="<? the_permalink()?>"><? the_title(); ?></a></li>
<?
endwhile; endif;   
wp_reset_query(); 
}
echo footLink(12);

this one just displays the recent entries and not posts from the category id 12

Any idea why?

NVM

it should be query_posts(β€˜cat=’.$cat.β€˜β€™);