鼠标拖动图片移动

<!DOCTYPE html> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>鼠标拖动图片移动</title>
<script type="text/javascript" src="js/jquery-1.11.3.js"></script> 
<script type="text/javascript"> 
    $(function(){ 
        $("html").mousemove(function(e){ 
            $("#a").css("left",e.pageX).css("top",e.pageY); 
        }); 
    }); 
</script> 
<style type="text/css"> 
    .a { 
        width:200px; 
        height:100px; 
        position:absolute; 
        background-color:rgb(0,0,0); 
    } 
</style> 
</head> 
<body> 
    <img src="img/duihuan.png" id="a" name="a" class="a" > 
    只做了一个简单的实例 
</body> 
</html>