To display the form you use
<?php include (TEMPLATEPATH . '/searchform.php'); ?>
To do that you need to have searchform.php, which should be part of your theme in the same directory and should look something like:
<form method="get" id="searchform" action="<?php bloginfo('url'); ?>/">
<label class="hidden" for="s"><?php _e('Search this site:'); ?></label>
<input type="text" value="<?php the_search_query(); ?>" name="s" id="s" />
<input type="submit" id="searchsubmit" value="Search" />
</form>
By editing that HTML you can add a value. I THINK that the get search form gets the results – maybe?