function openWindow(){
        var oPen=confirm("是否打开新窗口");
        if(oPen==true){
            var url=prompt("确定打开网址？"，"http://www.imooc.com/");
            if(url!=null){
                window.open(url,"_blank","width=400px,height=500px,menubar=no,toolbar=no");
            }
            else{
                alert("结束");
            }
        }
        else{
            alert("结束")；
        }
    }