Like this:
<div style="border: 1px solid red; height:200px; width:400px; z-index:2; top:100px; left:200px; position:absolute; ">
</div>
<div style="border: 1px solid black; height:200px; width:100%;z-index:1; background-color:white; position:absolute;">
</div>
<div style="border: 1px solid Green; height:200px; width:100%;z-index:3; top:200px; background-color:white; position:absolute; ">
</div>