Js获取当前时间

<script language="javascript" type="text/javascript">
//js获取日期
function time()
{

var now= new Date();

var year=now.getFullYear();

var month=now.getMonth();

var date=now.getDate();

//写入相应id

document.getElementById("res_date").value=year+"-"+(month+1)+"-"+date;


} 
</script>