How can i center?

How can i center the image in this script?

<div class="usericon">     
        <?php
                if ((isadminloggedin()) || (!$vars['entity']->isBanned())) {
         ?><a href="<?php echo $vars['entity']->getURL(); ?>" class="icon" ><?php
                }
               
        }
       
        ?><img src="<?php echo $vars['entity']->getIcon($vars['size']); ?>" border="0" <?php echo $align; ?> title="<?php echo htmlentities($vars['entity']->name, ENT_QUOTES, 'UTF-8'); ?>" <?php echo $vars['js']; ?> /><?php

                if (!$override) {
       
        ?></a><div class="sub_menu">
                <a href="<?php echo $vars['entity']->getURL(); ?>"><h3><?php echo $vars['entity']->name; ?></h3></a>
                <?php
                        if (isloggedin()) {
                                $actions = elgg_view('profile/menu/actions',$vars);
                                if (!empty($actions)) {
                                       
                                        echo "<div class=\"item_line\">{$actions}</div>";
                                       
                                }
                                if ($vars['entity']->getGUID() == $vars['user']->getGUID()) {
                                        echo elgg_view('profile/menu/linksownpage',$vars);
                                } else {
                                        echo elgg_view('profile/menu/links',$vars);
                                }                                      
                        } else {
                                echo elgg_view('profile/menu/links',$vars);
                        }
                ?>
        </div> 
</div>