pause the game in enterframe

Hello Guys , I have a problem that I can´t resolve in several days, how can I pause my game using an enterframe method, I try with , removeEventListener, for pause and addEventListener, for play, and it works, but the problem comes when I destroy an enemy in the game and I pause and play the game , the simulator show an error,and I think is for how I can addEventListener an objetc that I remuve previously.

Please help me with this.

Thanks.