ActionScript 3.0 :: Passing A Sprite Into A Function

I'm creating a jeopardy like game and have run into a problem. when you click on the dollar amount a create a sprite on the fly and inside the sprite is a shape and some textfields. One of the fields is an input box. once you enter in an answer and press enter I create another sprite with a textfield inside it to let you know if the answer is right or wrong. Herein lies the problem. once your told if your right or wrong, I want the sprites to stay on the screen for 3 seconds then disappear.

I can get them to stay on the screen, but I can't get then to disappear because I can't pass the sprite to the function that I created to remove them. So everything works except the remove function. This is the error I get when the remove function runs: "TypeError: Error #1009: Cannot access a property or method of a null object reference."

I'd post some code but its broken What I'm looking for is just information on how to assign a sprite to a variable so I can use it in a function. if thats not possible then is there a better way to do what I need done?