ul#main_menu {
 margin: 0;
  padding: 0;
  list-style: none;
  font-size:100%;
   text-align: center;
   width: 900px;
}

ul#main_menu li {
	margin: 0;
	border: 0 none;
	padding: 0px 0px 0px 0px;
	float: left; /*For Gecko*/
	display: inline;
	list-style: none;
	position: relative;	
	background: none;
	height: 50px;
}