Flash games hack, score is 49700?? How to improve flash games security?

Question

I have 2 flash games (written in as3). Both the highscore value being hacked. The normal range of each game score is not more than 5000 (normal users, will only get 2000 - 3000

Answer 1

Would not simply running the game on the server side prevent score hacking? If the game is being run as a random game then you send the random values to the user's browser there wouldn't be much sense in them attempting to cheat,even de-compiling the flash file wouldn't give them an advantage.