*{ margin:opx auto; padding:0px;}
#leibie{ 500px; height:36px; border:1px solid #03F;}
.yuyan{ float:left; 100px; height:36px; text-align:center; line-height:36px; vertical-align:middle; font-weight:bold;}
.yuyan:hover{ cursor:pointer; background-color:#96C; color:white;}
#yuyan2{ 100px; height:100px; position:relative; top:36px; left:-100px; background-color:#0F0; display:none}
#yuyan3{ 100px; height:100px; position:relative; top:36px; left:-100px; background-color:#FF0; display:none}
#yuyan4{ 100px; height:100px; position:relative; top:36px; left:-100px; background-color:#0FF; display:none}
#yuyan5{ 100px; height:100px; position:relative; top:36px; left:-100px; background-color:#F00; display:none}
</style>
<body>
<div id="leibie">
<div class="yuyan" onmouseover="xianshi('yuyan2')" onmouseout="yincang('yuyan2')">.net</div>
<div style="float:left; 0px">
<div id="yuyan2"></div>
</div>
<div class="yuyan" onmouseover="xianshi('yuyan3')"onmouseout="yincang('yuyan3')">java</div>
<div style="float:left; 0px">
<div id="yuyan3"></div>
</div>
<div class="yuyan" onmouseover="xianshi('yuyan4')" onmouseout="yincang('yuyan4')">php</div>
<div style="float:left; 0px">
<div id="yuyan4"></div>
</div>
<div class="yuyan" onmouseover="xianshi('yuyan5')" onmouseout="yincang('yuyan5')">IOS</div>
<div style="float:left; 0px">
<div id="yuyan5"></div>
</div>
</div>
</body>
<script type="application/javascript">
function xianshi(d)
{
var aa = document.getElementById(d);
aa.style.display = "block";
}
function yincang(d)
{
var aa = document.getElementById(d)
aa.style.display="none";
}
</script>