Please be aware if you are doing the "overnight" stay in Sri Lanka that you do not get your luggage at the airport - we wrongly thought that as we had to leave the airport we would get our luggage but were told it would be held there until we returned for our flight. Also fill in the immigratation form on the plane - we were told we did not have to but when we got to SL desk we had to do it there.
When you get off the plane go down the long passage way following the transit sign and at the end you will see an information desk and down a few steps behind it is the NIGHT STOP desk. Present your tickets and passports there and they will give you paper work to take to the SL desk down stairs. Go through immigration - down the stairs - turn right - throught the Foreigners Customs channel on your left and through a door marked EXIT. Just a little way through the door on your right is the SL desk where you give in the paper work and wait for transport to your hotel.
It is all very easy - we went in a mini bus with 2 girls who were dropped off 10 minutes from the airport - we carried on for another 30 to a beach resort but with only our travelling clothes it wasn't much fun The worst was yet to come - we got there at 2pm and had lunch, afternoon cup of tea and then dinner and were then told that our wake up call was to be at 2am and we would leave for the airport at 2.15 am as it was an International flight and we had to be there 3 hours before. Got to the airport and were given our boarding cards and sat there until 5.30 am. when 30 of us boarded the flight to Goa.