Ennél a vízszintes menükódnál mit kell átírnom ahhoz, hogy a menü minden felbontásban középen helyezkedjen el?

<ul id="menu">

<li class="first" id="home">

<a href="http://">Menü1</a></li>

<li id="single">

<a href="http://">Menü2</a></li>

<li id="dropdown">

<a href="http://">Menü3</a></li>

<li id="dropline">

<a href="http://">Menü4</a></li>

<li id="dropdown">

<a href="http://">Menü5</a></li> </ul>

<style type="text/css">

#menu {padding:0; margin:0; list-style:none; width:940px; height:37px; position:absolute; top:181px; left:164px;}

#menu li {position:relative; float:left;}

#menu li a {display:block; height:33px; padding:0; width:88px; float:left; color:#625D4B; text-decoration:none; font-family: ARIAL; font-size:12px; text-align:center; cursor:pointer; background: url(http://); line-height:33px;}

#menu li a b {position:relative;}

#menu li a:hover,

#menu li a:active,

#menu li a:focus,

.home #menu li#home a,

.single #menu li#single a,

.dropdown #menu li#dropdown a,

.dropline #menu li#dropline a,

.flyout #menu li#flyout a,

.support #menu li#support a,

.contact #menu li#contact a

{background: url(http://) no-repeat right top; cursor:pointer; color:#808080;}

* html #menu li a:hover,

* html #menu li a:active,

* html #menu li a:focus,

* html .home #menu li#home a,

* html .single #menu li#single a,

* html .dropdown #menu li#dropdown a,

* html .dropline #menu li#dropline a,

* html .flyout #menu li#flyout a,

* html .support #menu li#support a,

* html .contact #menu li#contact a

{background:none; filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='http://', sizingMethod='scale');}

#menu li a:hover b,

#menu li a:active b,

#menu li a:focus b,

.home #menu li#home a b,

.single #menu li#single a b,

.dropdown #menu li#dropdown a b,

.dropline #menu li#dropline a b,

.flyout #menu li#flyout a b,

.support #menu li#support a b,

.contact #menu li#contact a b

{cursor:pointer;}

--> </style>