html5判断浏览器来源并跳转

<script type="text/javascript">
        var system ={};
       var p = navigator.platform;
       system.win = p.indexOf("Win") == 0;
       system.mac = p.indexOf("Mac") == 0;
       system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);
       if(system.win||system.mac||system.xll){//如果是电脑跳转到
       alert("请从手机端访问");
               window.location.href="http://52td.top";
       }else{  //如果是手机,跳转到
            //console.log(11111);
            window.location.href="#";
       }
</script>