Want to show author name in post

[pxforti]

Hi, I want to show author name in post. I can get username to display, but I want the author name; eg, instead of jsmith I want to display John Smith.
What code do I need to do this? Currently the template uses the following code to display the Joomla username:
$_showauthor = get_option('showauthor_joomla');
and
<?php the_time('F jS, Y'); if($_showauthor){ ?> <i><?php echo JText::_('WP_BY'); ?> <?php the_author(); echo '</i>';} ?>

Thanks

Joomla 1.5.15
Wordpress 2.8.6