Checking for a Screen Connection in Background - Without using SY-BATCH

Hi

I have a requirement to resolve/patch a particularly dumb development, namely calling a pop-up box in a BADi.

Standard SAP creates an IDOC to post an MM invoice, and whilst the IDOC is created in status 64, the process terminates and creates a short dump. Surprisingly though in this process SY-BATCH is initial.

Basically, I have a pop-up box called via POPUP_TO_CONFIRM that obviously short dumps in background, and I need to prevent this. I don't think the short dump is catchable.

How can I check for a screen connection without using SY-BATCH?

Thanks

Chris