<div id='container'> <div id='d1'>d1</div> <div id='d2'>d2</div> </div>
#container { position: relative; } #d1 { height: 100px; background-color: blue; z-index: 200; } #d2 { z-index: 200; margin-top: -50px; height: 200px; background-color: red; }