<script src="jquery.js"></script>
<script type=text/javascript>
$(document).ready(function(){
$("button").click(function(){

$.ajax({
type: "post",
url: 'cgi-bin/add',
async: false,

data: $("#save").serialize(),

contentType: "application/x-www-form-urlencoded; charset=utf-8",

cache: false,
success: function(data) {

$('#result').text(date);
} 
});

});
});
</script>

<form id="save">
<p>
<input id="a" type=text size=5 name=a> + <input id="b" type=text size=5 name=b> = <span id=result></span></p>
<p>
<button>计算</button>
</p>
</form>

结果返回页面闪烁一下就没显示了，是什么原因