dynamic link to category

Hi,

Like the title says, I am trying to get a dynamic link of a category.

Actually I am building a custom archive template, which displays the 5 last posts in each category.

Here is my code :

<?php
            // get all the categories from the database
            $cats = get_categories();

                // loop through the categries
                foreach ($cats as $cat) {

                ?>
                <div class="<?php my_post_class(); ?>">
                <?php
                    // setup the cateogory ID
                    $cat_id= $cat->term_id;
                    // Make a header for the cateogry
                    echo "<span class='position-band'><span class='band-side'></span><span class='band-small-title'>".$cat->name."</span><span class='band-right'></span></span>";

					?>
                    <div class="clear"></div>
                    <?php
                    // create a custom wordpress query
                    query_posts("cat=$cat_id&posts_per_page=5");
                    // start the wordpress loop!
                    if (have_posts()) : while (have_posts()) : the_post(); ?>

                        <?php // create our link now that the post is setup ?>
                        <div class="title-cat"><a href="<?php the_permalink();?>"><?php the_title(); ?></a></div>
                        <?php echo '<br/>'; ?>

                    <?php endwhile; ?>

	<a href="?cat=<?php $cat=$cat_id ?>">(View more...)</a>

				<?php	endif; // done our wordpress loop. Will start again for each category ?>
                    </div>
                                <?php } // done the foreach statement ?>

                </div>

If this code works well, I would like to make a View More link going to the specific category page.

Actually my view more link doesn’t work. It goes to index page ??

<a href="?cat=<?php $cat=$cat_id ?>">(View more...)</a>

What’s wrong with it ?

Thanks for your help.