Como centrar izzymenu

[ricardogomezp]

Ok gracias, el código sería:

Código HTML:

<div id="MainMenu"> <!--Menu-->
	<div id="tab">
	  <ul>
		<li><a href="home.html"><span>Inicio</span></a></li>
		<li><a href="about.html"><span>Objetivos</span></a></li>
		<li><a href="contact.html"><span>Blog</span></a></li>
		<li><a href="subpage.html"><span>Contáctenos</span></a></li>
	  </ul>
	</div>
</div> 

Y el CSS:

Código:

#MainMenu {width:742px;
	height:28px;
	background:#051F49;
	border-color:#9AB6D2;
	border-style:solid;
	border-width:0 0 3px;
	margin:0;
}

#tab {top:0;
	height:0;
	background:repeat-x top;
	margin:0;
}

#tab ul {list-style:none;
	float:left;
	margin:0 auto;
	padding:0;
}

#tab li {display:inline;
	float:left;
	margin:0 1px 0 0;
	padding:0;
}

#tab a {background:url(../images/bright_115.gif) no-repeat right top;
	text-decoration:none;
	border:0;
	display:block;
	float:left;
	margin:0;
	padding:0;
}

#tab a span {display:block;
	background:url(../images/bleft_115.gif) no-repeat left top;
	font-family:"Times New Roman", Times, serif;
	font-size:16px;
	color:#051F49;
	font-weight:700;
	line-height:27px;
	padding:0 22px;
}

#tab a:hover,#tab li.item_active a {background-position:right bottom;
}

#tab a:hover span,#tab li.item_active a span {background-position:left bottom;
	color:#051F49;
	font-weight:700;
	font-style:normal;
	text-decoration:none;
}
.dropmenudiv {position:absolute;
	top:0;
	float:left;
	display:block;
	visibility:hidden;
	background:#051F49;
	color:#051F49;
	z-index:100;
	text-decoration:none;
	border-color:#9AB6D2;
	border-style:solid;
	border-width:0 0 3px;
	padding:0;
}

.dropmenudiv ul {list-style:none;
	padding:0;
}
.dropmenudiv li {display:inline;
	margin:0;
	padding:0;
}

.dropmenudiv a:link,.dropmenudiv a:visited {width:180px;
	display:block;
	border:0;
	color:#051F49;
	background:url(images/bleft_115.gif) no-repeat left top;
	font-weight:700;
	font-style:normal;
	text-decoration:none;
	margin:0 1px 0 0;
	padding:0;
}

.dropmenudiv a span {display:block;
	line-height:27px;
	background:url(images/bright_115.gif) no-repeat right top;
	font-family:"Times New Roman", Times, serif;
	font-size:16px;
	color:#051F49;
	float:none;
	padding:0 22px;
}

.dropmenudiv a:hover {border:0;
	background-position:left bottom;
	font-weight:700;
	font-style:normal;
	text-decoration:none;
	color:#051F49;
}

.dropmenudiv a:hover span {background-position:right bottom;
	color:#051F49;
	font-weight:700;
}

Talvez sirva decir que esto tambien lleva un .js para que se produzca un efecto aunque no creo que el problema esté allí.