<script>

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){//如果是电脑跳转到百度

        window.location.href="http://www.baidu.com/";

    }else{  //如果是手机,跳转到谷歌

        window.location.href="http://www.google.cn/";

    }

</script>