我用setInterval做定时执行怎么IE下不能用

ie下是没问题的<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head><body>
<script language="JavaScript">
<!--test=function()
{
alert('dddd');
}
setInterval("test()",1000);//-->
</script>
</body>
</html>