为什么我点击按钮没反应
<!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 cof=confirm("是否打开此网页?");
if(cof)
{ var pro=prompt("确定打开的网址:","www.baidu.com/");
window.open(pro,'_blank','height=500,width=400,menubar=no,toolbar=no');
}
}
</script>
</head>
<body>
<input type="button" value="新窗口打开网站" onclick="openWindow()" />
</body>
</html>