<!DOCTYPE html>
<html>
<head>
<title> new document </title>
<meta http-equiv="Content-Type" content="text/html; charset=gbk"/>
<script type="text/javascript">
function xi(){
var y=confirm("是否打开？");
if(y=true)
{
window.open('http://www.imooc.com/','width=400','height=500','menubar=no','toolbar=no');
}
else
{
alert("打开失败！");
}
}
</script>
</head>
<body>
<input type="button" value="新窗口打开网站" onclick="xi()" />
</body>
</html>
==true
alert本身就是一个警告弹窗啊