You are posted extremely brief questions. This is an issue because this makes it harder to understand your context. As an example: in your previous question I guessed as to what would be your end goal, but you didn't respond at all, so I'm still unsure if that is what you need.
For this one, I suspect you need to change the CloseReqFcn, but since you provide so little detail, I can't even guess what you might need. What pictures are you talking about? What images? What do you mean by background? What do you mean with screen in this case?
If you address these issues, your question will automatically re-open.
