请大家看看有错吗??为什么显示不出来后面的日和时间
<script type="text/javascript">
var attime;
function clock(){
var time=new Date();
attime= time.getFullYear()+"-"+time.getMonth()+"-"+time.getDay()+"."+time.getHours()+":"+time.getMinutes()+":"+time.getSeconds();
document.getElementById("clock").value = attime;
}
var su=setInterval(clock,2000)
</script>
</head>
<body>
<form>
<input type="text" id="clock" size="50" />