do you have xlsApps declared at the very top of your module? I don't see how Form_Close knows what it is.
EDIT:
I also think the syntax is .Close False but not sure. What you have looks more like Excel syntax.
Then again, you don't specify which workbook in the Workbooks collection you are trying to close. You specify which one to add to the collection (sgtrxlFileName) but not which one to close. When doing this, I always create objects for the app, book, and sheet. That way, it's clear and easy as to which one I want to refer to. Haven't done this for a while so I'm guessing a bit, but I lean towards Access not knowing which object to close.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.