#start {
	position:absolute;
	top: 50%;
	left: 50%;
	width:50em;
	height:20em;/*18em;*/
	margin-top: -14em; /*set to a negative number 1/2 of your height*/
	margin-left: -25em; /*set to a negative number 1/2 of your width*/
	border: none;
	background-color: #fff;
	text-align: center;
	vertical-align: middle;
	font-family: verdana,sans-serif;
	font-size: 11px;
}