Sri Lankan and Emirates share http://www.skywards.com
If you sign up now, you might get a first flight bonus. Can't remember whether it is for first flight booked after signup, or just flown after signup, but definitely take care of it before the weekend. I think it's something like 3,500 miles for J travel (though you didn't mention class of service). Also, 30% bonus miles on Emirates for booking online, so there are some very good bonuses. Skywards is almost as generous as United in mileage earning, though the miles expire and the redemptions are much higher in many cases.