confirm窗口都出不來(lái)，求大神解惑！
<!DOCTYPE html>
<html>
?<head>
? <title> new document </title>?
? <meta http-equiv="Content-Type" content="text/html; charset=gbk"/>??
? <script type="text/javascript">?
???? function openWindow(){
?????? var cfm=confirm("open or not?");// 新窗口打開(kāi)時(shí)彈出確認(rèn)框，是否打開(kāi)
??????? if(cfm==true)
???????? {var url=prompt("url?","http：//yifanck.cn/");
??? // 通過(guò)輸入對(duì)話框，確定打開(kāi)的網(wǎng)址，默認(rèn)為 http：//yifanck.cn/
?????????? if(url!=null)
????????????? {var open=window.open('url','_blank','width=400,height=500,menubar=no,toolbar=no')';
??? //打開(kāi)的窗口要求，寬400像素，高500像素，無(wú)菜單欄、無(wú)工具欄。
??????? }
??????? else
????????????? {alert('bye!');? } }
???????????
??????? else
???????? {alert('!');}
? }
? </script>
?</head>
?<body>
?? <input type="button" value="新窗口打開(kāi)網(wǎng)站" onclick="openWindow()" />
?</body>
</html>
2019-07-28
if(url!=null)
????????????? {var open=window.open('url','_blank','width=400,height=500,menubar=no,toolbar=no')';
這一行代碼錯(cuò)了，結(jié)尾的單引號(hào)