<div style="width:300px; float:left;">
<div onmouseover="testOnmouseOver()" onmouseout="testOnmouseOut()" id="lef1"; style="width: 500px; background-color:#99ccff; ">gggg
</div>
<div id="lef"; style="width: 500px; background-color:#99ccff; ">gggg
</div>
</div>
<div id="rev1"; style="width: 500px; float:right; background-color:#ffff66; height: 182px;">
</div>
</body>
</html>
<script type="text/javascript" src="http://files.cnblogs.com/914556495wxkj/jquery-1.4.1.js"></script>
<script type="text/javascript">
function testOnmouseOver() {
$("#rev1").show();
}//显示
function testOnmouseOut() {
$("#rev1").hide();
}//隐藏
$(function () {
$("#rev1,#rev2,#rev3").hide()//隐藏
})
$(function () {
$("#test").append("<a href='http://baidu.com'>这是新加的</a>");
})
</script>