<!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 open = confirm("是否打开网页？");
if (open == true)
{
var url = prompt ("请输入要打开的网址","http://www.imooc.com/");
if (url ! = null)
{
window.open(url,"_blank",'width=400px,height=500px,menubar=no,toolbar=no') ;
}
else
{
alert("再见!");
}
}
else
{
alert("再见!");
}
}
</script>
</head>
<body>
<input type="button" value="新窗口打开网站" onclick="openWindow()" />
</body>
</html>
if(url != null) 感叹号和等号之间不要有空格