请问下为什么点了一下按钮后页面啥都没有?
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
function open(){
var win=confirm('你确定打开这个窗口吗?')
if(win==true){
var win1=prompt('打开下面默认的网址?','http://www.imooc.com')
if(win1!=null){
window.open(win1,'_blank','width=300,height=500,toolbar=no,scrollbars=yes,status=no,menubar=no')}
else{alert('byebye')}
}
else{alert('see you')}
}
</script>
</head>
<body>
<input type="button" value="点击我,打开新窗口" onClick="open()"/>
</body>
</html>