1<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2<html>
3<head>
4<style>
5body { margin: 0px; }
6.outer {
7        margin: -100px;
8	width: 400px;
9        height: 500px;
10	background-color: yellow;
11}
12.outer:hover {
13        background-color: red;
14}
15.inner {
16	visibility: hidden;
17	width: 100%;
18	height: 50%;
19	background-color: cyan;
20}
21</style>
22</head>
23
24<body>
25<div class="outer" 
26     onmouseover="firstChild.style.visibility='visible'" 
27     onmouseout="firstChild.style.visibility='hidden'"><div class="inner"></div></div>
28</body>
29</html>
30