代码如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>改变文本框大小</title>
<style type="text/css">
*{margin:0px;padding:0px;}
form{margin:40px 40px;border:1px solid #666;width:600px;}
.msg{margin:10px 10px;}
.changeBtn button{margin-left:8px;margin-bottom:8px;}
.comment{width:300px;height:170px;}
</style>
<script src="scripts/jquery-2.0.3源码.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
var $comment=$(".comment");
$(".smalle").click(function(){
if($comment.height()>50){
$comment.height($comment.height()-50);
}
});
$(".big").click(function(){
if($comment.height()<500){
$comment.height($comment.height()+50);
}
});
});
</script>
</head>
<body>
<form>
<div class="msg">
<div class="changeBtn">
<button class="smalle">缩小</button>
<button class="big">放大</button>
</div>
<div >
<textarea class="comment" >这里是我要评论的内容 </textarea>
</div>
</div>
</form>
</body>
</html>
为什么点击之后改变大小瞬间又被弹回原来的大小呢，求教！
