Do I need the tags 'html' and 'body' in the following code?
===

I'm creating a Page Template for a WordPress site.

In the file newpagetemplate.php I currently have this code, and this code only:

>    <html>
>    <body>
>    <?php
>    /*
>    Template Name: Salespage
>    */
>    ?>
>    <div>
>        <?php if (have_posts()) : while (have_posts()) : the_post(); ?>
>            <?php the_title(); ?>
>            <?php the_content(); ?> 
>        <?php endwhile; endif; ?>
>    </div>
>    </body>
>    </html>

I'll need to make amendments, to set values for margins, fonts etc.

In the above code, do I need the 'html' and 'body' tags?

(If I take those tags out, a page with this page template applied still displays ok.)