Login... Not Working

<?phpheader('content-type:text/css');$fakeheight = $_COOKIE['height'];$number = 174;$realheight = $fakeheight - $number;?>#login_container {	position: absolute;	z-index: 0;	height: <?=$realheight?>;	width: 599px;	margin: -207px auto 0 auto;	padding: 0;	background-image: url(../img/login_container.gif);	background-position: top center;	background-repeat: repeat-y;}