为什么我的完全打不开
<!DOCTYPE html>
<html>
<head>
<title> new document </title>
<meta http-equiv="Content-Type" content="text/html; charset=gbk"/>
<script type="text/javascript">
function open(){
var con=confirm("你确定吗");
if(con ==true)
{
var url=prompt("请输入：" ," http：//www.imooc.com");
if(url!=null)
{
window.open(url, '_blank','width:400,height:500,menubar=no,toolbar=no);
}
else{
alert("再见");
}
}
else
{
alert("再见");
}
}
</script>
</head>
<body>
<input type="button" value="点击我，有惊喜" onclick="open()" />
</body>
</html>
