MyBB Community Forums

I am trying to change the header but nothing I do will edit it. Everything I type remains the same.
I am trying to implement this:
[SPOILER]

<div id="container">
                <a name="top" id="top"></a>
                <div id="header">
                        <div class="logo"><a href="{$mybb->settings['bburl']}/index.php"><img src="{$theme['logo']}" alt="{$mybb->settings['bbname']}" title="{$mybb->settings['bbname']}" /></a></div>
                        <div class="menu">
                                <ul>
                                        <li><a href="{$mybb->settings['bburl']}/search.php"><img src="{$theme['imgdir']}/toplinks/search.gif" alt="" title="" />{$lang->toplinks_search}</a></li>
                                        <li><a href="{$mybb->settings['bburl']}/memberlist.php"><img src="{$theme['imgdir']}/toplinks/memberlist.gif" alt="" title="" />{$lang->toplinks_memberlist}</a></li>
                                        <li><a href="{$mybb->settings['bburl']}/calendar.php"><img src="{$theme['imgdir']}/toplinks/calendar.gif" alt="" title="" />{$lang->toplinks_calendar}</a></li>
                                        <li><a href="{$mybb->settings['bburl']}/misc.php?action=help"><img src="{$theme['imgdir']}/toplinks/help.gif" alt="" title="" />{$lang->toplinks_help}</a></li>
                                </ul>
                        </div>
                        <hr class="hidden" />
                        <div id="panel">
                                {$welcomeblock}
                        </div>
                </div>
                <hr class="hidden" />
                <br class="clear" />
                <div id="content">
                        {$pm_notice}
                        {$bannedwarning}
                        {$bbclosedwarning}
                        {$unreadreports}
                        {$pending_joinrequests}
                        <navigation>
                        <br />

[/SPOILER]

But it keeps staying aligned to the right and showing this:

It says its saving, but when I reload my forums, I see no difference.
How can I make it so I can add "home" and make it centered? My friend told me I have to reinstall my forums and I really don't want to do that..