为什么显示不出来
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>电子时钟</title>
<script type="text/javascript">
window.onload=function(){
var myDate=new Date();
var year=myDate.getFullYear();
var month=myDate.getMonth()+1;
var date=myDate.getDate();
document.getElementById("show").innerHTML=year+"年"+month+"月"+date+"日"；
</script>
</head>
<body>
<div id="show">显示时间的位置</div>
</body>
</html>
