I've a function which reads a value from a cell... it's

Function ReadCell(msheet, mCell)
ReadCell = ActiveWorkbook.Worksheets(msheet).Range(mCell).Val ue
End Function

.... and normally works fine.

But if there's a second Workbook open, closing Excel invokes
'Run-time error '9': Subscript out of range' on the ReadCell= line.

Private Sub Workbook_BeforeClose in Workbook 1 is calling this.
Variables msheet and mcell are both present, and correct.

The erorr only occurs when Workbook 2 is 'active'. In other words
calling the function from Workbook 2's immediate window causes the
error, but not Workbook 1.

I hope that makes sense... it's the same immediate window, the
difference is only which underlyng workbook is open (has focus?).

I suspect it's something to do with Closing book 2 somehow using 1's
before close event but I don't quite understand it, or how to get
round it. Any help appreciated.

Thanks - Kirk