How to get particular category and post

<?php
$cat2=12;                                                                            //  The 12 is a category id
$yourcat2 = get_category($cat2);
?>
<div>
<div>
<div><?php echo $yourcat2->name; ?></div>                     // Get ategory name
<div>
<h3><?php echo $yourcat2->slug; ?></h3>                          // Get category slug
<ul>
<?php
query_posts(‘showposts=4&cat=12‘);                     // The 4 is a display post count and 12 is a  category id
while(have_posts()) : the_post();
?>
<li><a href=”<?php the_permalink() ?>” rel=”bookmark”><?php the_title(); ?></a></li>                    // Get post title with url
<?php endwhile;?>
</ul>
</div>
</div>
</div>