Center DIV with Dynamic Height

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>