<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<script language="javascript" type="text/javascript" src="jquery-1.7.2.js"></script>
<script language="javascript" type="text/javascript">
$(document).ready(function(){
$("#hide").click(function(){
$("p").hide(1000);
$("#show").click(function(){
$("p").show(1000);
});
});
});
</script>

<p>

大家好，欢迎学习jquery
</p>

<button id="show">显示</button>
<button id="hide">隐藏</button>