Flash game assignment with many TypeError: Error #1009

hey all,
I am new to this forum and studying actionscript for past few months in college. I am a student with a game to build as an assignment. It’s our first time making a game and while im really enjoying actionscript, it is very difficult and get’s confusing very quickly.

My game is a maze game where the player has to rescue 6 hostages along a set path and bring them to a rescue zone. The player lose’s health if hit by enemys and game is over if health runs out or the time runs out. The game is won if all hostage are rescued and the player gets to the exit before time and health runs out.

When the time runs out the game go’s to the gameover screen without any problems. However when health runs out there are many TypeErrors of Error #1009. Same happens when i try to exit/win the game.

I have uploaded my file as a compressed .zip which contains the .fla file which is saved as Flash CS4. If anyone could help me with what the problems might be and how to fix them I would be delighted as I am totally stuck and confused with what to do trying to fix it. Help really appreciated.

Cheers
Barry