var ua = navigator.useragent;
var ipad = ua.match(/(ipad).*os\s([\d_]+)/),
isiphone = !ipad && ua.match(/(iphone\sos)\s([\d_]+)/),
isandroid = ua.match(/(android)\s+([\d.]+)/),
ismobile = isiphone || isandroid;
if(ismobile) {
    location.href = '/m';
}