Southern Railway today announced chnage in composition in Shatabdi Express on August 6 and 7.A statement here said as coach composition of train no 12007 Chennai Central-Mysore Shatabdi Express and train no 12008 Mysore-Chennai Central Shatabdi Express will be changed, there may be changes in the numbers alloted to reserved passengers.In order to assist the passengers to ascertain the revised seating information, a help desk will function at Chennai Central Railway Station during the above period.Passengers may approach the help desk at Chennai Central railway station to obtain the reallotted seat numbers before boarding the train. The information can also be obtained through the universal number 139 which is accessible from anywhere in the country without dialing any STD code, the statement said.