<div id="myDiv" style="position:absolute; left:168px; top:251px; width:192px; height:66px; z-index:1; background-color:red;"> an z-index of 1. </div> <div style="position:absolute; left:168px; top:251px; z-index:12; height:50; background-color:blue;"> a z-index of 12. </div> <button onclick="myDiv.style.zIndex = 20;"> Bring red to front </button>