sure thing:

html:

<div id="bottom">

        <div id="top">stuff in the top</div>

</div> 

css:

#bottom{

    width: 200px;
    height: 200px;
    background-color: black;

}

#top{

    width:100px;
    height:200px;
    background-color:red;

    z-index: 999;      <-- the z index property will push the #top div above the bottom div

}