Keeping Header Centered / Static

[qubed]

Hi Everyone -

I am a bit of a novice in regards to knowing how to do this, however, how do I go about having a static / centered header on my forum. The current size and width of my image is 420x184 and I am trying to center it and have it adjust to the width and stay centered no matter the width a user may have their browser sized to.

Is there a way to do this? My current code in my header is as follows and I do not know what I need to adjust if this is even the right place to do so:

<a name="top"></a>

<div id="wrapper" style="width:$stylevar[outertablewidth];">

<!-- adding your own banner to template Ad Header Logo will cause the banner to display, but be sure to assign it the class "topBanner" so that it floats right and displays properly -->

<if condition="$ad_location['ad_header_logo']">$ad_location[ad_header_logo]</if>

<!-- here we set up your Board's title as the main deading and then swap in the logo image with CSS -->

<h1 id="logo"><a href="$vboptions[forumhome].php$session[sessionurl_q]" title="$vboptions[bbtitle]">$vboptions[bbtitle]</a></h1>

<!-- nav buttons bar -->

<ul id="navi">
		<if condition="$show['member']">
			<li><a href="usercp.php$session[sessionurl_q]">$vbphrase[user_cp]</a></li>
		</if>
		<if condition="$show['registerbutton']">
			<li><a href="register.php$session[sessionurl_q]" rel="nofollow" style="color:#FFFFFF;">$vbphrase[register]</a></li>
		</if>
		$template_hook[navbar_buttons_left]
		<li><a href="faq.php$session[sessionurl_q]" accesskey="5">$vbphrase[faq]</a></li>
		<if condition="$show['communitylink'] AND $show['popups']">
			<li><a id="community" href="$show[nojs_link]#community" rel="nofollow" accesskey="6">$vbphrase[community]</a> <script type="text/javascript"> vbmenu_register("community", true); </script></li>
		<else />
			<if condition="$vboptions['enablememberlist']">
				<li><a href="memberlist.php$session[sessionurl_q]">$vbphrase[members_list]</a></li>
			</if>
			<if condition="$show['quick_links_groups']">
				<li><a href="group.php?$session[sessionurl]">$vbphrase[social_groups]</a></li>
			</if>
		</if>
		<li><a href="calendar.php$session[sessionurl_q]">$vbphrase[calendar]</a></li>
		<if condition="$show['popups']">
			<if condition="$show['searchbuttons']">
				<if condition="$show['member']">
				<li><a href="search.php?$session[sessionurl]do=getnew" accesskey="2">$vbphrase[new_posts_nav]</a></li>
				<else />
				<li><a href="search.php?$session[sessionurl]do=getdaily" accesskey="2">$vbphrase[todays_posts]</a></li>
				</if>
				<li id="navbar_search"><a href="search.php$session[sessionurl_q]" accesskey="4" rel="nofollow">$vbphrase[search]</a> <if condition="$show['quicksearch']"><script type="text/javascript"> vbmenu_register("navbar_search", true); </script></if></li>
			</if>
			<if condition="$show['member']">
				<li id="usercptools"><a href="$show[nojs_link]#usercptools" accesskey="3">$vbphrase[quick_links]</a> <script type="text/javascript"> vbmenu_register("usercptools", true); </script></li>
			</if>
		<else />
			<if condition="$show['searchbuttons']">
				<li><a href="search.php$session[sessionurl_q]" accesskey="4">$vbphrase[search]</a></li>
				<if condition="$show['member']">
				<li><a href="search.php?$session[sessionurl]do=getnew" accesskey="2">$vbphrase[new_posts_nav]</a></li>
				<else />
				<li><a href="search.php?$session[sessionurl]do=getdaily" accesskey="2">$vbphrase[todays_posts]</a></li>
				</if>
			</if>
			<li><a href="forumdisplay.php?$session[sessionurl]do=markread&amp;markreadhash=$bbuserinfo[securitytoken]" rel="nofollow">$vbphrase[mark_forums_read]</a></li>
			<if condition="$show['member']">
				<li><a href="#" onclick="window.open('misc.php?$session[sessionurl]do=buddylist&amp;focus=1','buddylist','statusbar=no,menubar=no,toolbar=no,scrollbars=yes,resizable=yes,width=250,height=300'); return false;">$vbphrase[open_contacts]</a></li>
			</if>
		</if>
		$template_hook[navbar_buttons_right]
		<if condition="$show['member']">
			<li><a href="login.php?$session[sessionurl]do=logout&amp;logouthash=$bbuserinfo[logouthash]" onclick="return log_out('$vbphrase[sure_you_want_to_log_out]')">$vbphrase[log_out]</a></li>
		</if>
</ul>
<div class="clear"></div>
<!-- / nav buttons bar -->

<div id="rounded-wrap">
<div id="rounded-top"><span></span></div>

<!-- content table -->
$spacer_open

$_phpinclude_output

$ad_location[ad_header_end]

Thanks in advance for the assistance. Please let me know if additional clarity is required.

qubed