识别访问端的操作系统

function PDD() {
            //平台、设备和操作系统
            var system = {
                win: false,
                mac: false,
                xll: false
            };
            //检测平台
            var p = navigator.platform;
            system.win = p.indexOf("Win") == 0;
            system.mac = p.indexOf("Mac") == 0;
            system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);
            //跳转语句
            alert(p);
            if (system.win) {
                alert("win");
            } else if (system.mac) {
                alert("mac");
            } else if (system.x11) {
                alert("X11 Or Linux");
            } else {
                alert("android");
            }

            if (system.win || system.mac || system.xll) {

            } else {
                window.location.href = "android.aspx";
            }
        }