实在是看不出来了，求帮助看看哪里错了，谢谢
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>jQuery动画特效</title>
</head>
<style>
div{
height:50px;
width:50px;
background:red;
position:relative;
left:100px;
top:100px;
}
</style>
<body>
<div></div>
<span></span>
<input id="left" type="button" value="左移" />
<input id="right" type="button" value="右移" />
</body>
<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js" type="text/javascript"></script>
<script>
$(function(){
$("#left").blind("click",function(){
$("div").animate({
left:"-=100px"
},1000,function(){
$("span").html("左移")
})
$("#right").blind("click",function(){
$("div").animate({
left:"+=100px"
},1000,function(){
$("span").html("右移")
})
})
})
</script>
</html>
