private void updateLocations(GameContainer gc, StateBasedGame sbg)
			throws SlickException {
		//Update the bullet's position.
		for(int i = 0;i<bulletList.size();i++){
			Bullet bullet = bulletList.get(i);
			bullet.move();

			// Removes bullets that go off screen.
			if ((bullet.returnX() > 639 || bullet.returnX() <= 1) || (bullet.returnY() < 1 || bullet.returnY() > 399)){
				bulletList.remove(i);     
			}
		}

		// Update the enemies' positions.
		for(int i = 0; i < enemiesOnScreen.size(); i++){
			Enemy enemy = enemiesOnScreen.get(i);

			enemy.move();

			// Removes enemies that go off screen. 
			// Decrements the player's health by 10.
			// Sets the multiplier back down.
			if (enemy.returnY() > 389 ){
				enemiesOnScreen.remove(i);
				Settings.health -= 10;
				score.setDefaultMultiplier();

				if(Settings.health == 0){
					sbg.addState(new Death(Game.DEATH_STATE));
					sbg.getState(Game.DEATH_STATE).init(gc, sbg);
					sbg.enterState(Game.DEATH_STATE);
				}
			}
		}
	}