Need to code a back button for a flash slide show

Im having difficulty coding two buttons to go back and forth 10 frames in Actionscript 3.0… i cant use movie clips because the animations cross over… I have gotten as far as getting the forward button to work correctly but the back button wont go in reverse… I tried coding it to go back ten frames but then it always goes back to the first frame rather than going in reverse ten frames… all tutorials i have seen on show how to control movieclips

CAN ANYONE PLEEEEEEEEEEEEAAAAAASSSSSEEE HELP!!!