Here is easy and best solution for center element with “position: absolute”
body,html{_x000D_
min-height:100%;_x000D_
}_x000D_
_x000D_
div.center{_x000D_
width:200px;_x000D_
left:50%;_x000D_
margin-left:-100px;/*this is 50% value for width of the element*/_x000D_
position:absolute;_x000D_
background:#ddd;_x000D_
border:1px solid #999;_x000D_
height:100px;_x000D_
text-align:center_x000D_
}_x000D_
_x000D_
_x000D_
<style>_x000D_
_x000D_
</style>_x000D_
_x000D_
<body>_x000D_
<div class='center'>_x000D_
should be centered verticaly_x000D_
</div>_x000D_
</body>
_x000D_