CSS

* { margin: 0; padding: 0; }
#page{display:table;overflow:hidden;margin:0px auto;}
*:first-child+html #page {position:relative;}/*ie7*/
* html #page{position:relative;}/*ie6*/

#content_container{display:table-cell;vertical-align: middle;}
*:first-child+html #content_container{position:absolute;top:50%;}/*ie7*/
* html #content_container{position:absolute;top:50%;}/*ie6*/

*:first-child+html #content{position:relative;top:-50%;}/*ie7*/
* html #content{position:relative;top:-50%;}/*ie6*/

html,body{height:100%;}
#page{height:100%;width:465px;}

HTML

<div id="page">
       <div id="content_container">
               <div id="content">
                     <p>your content</p>
               </div>
       </div>
</div>