弹出新窗口的javascript代码

直接在页面上写javascript代码：

<script language="javascript">
<!--
var gt = unescape('%3e');
var popup = null;
var over = "Launch Pop-up Navigator";
popup = window.open('', 'popupnav', 'width=500,height=500,resizable=0,scrollbars=auto'); // width=500,height=500为窗口长和宽
if (popup != null) {
if (popup.opener == null) {
popup.opener = self; }
popup.location.href = 'update.htm';
}
// -->
</script>