Can someone tell me why the following code generates the following error:

Dim regTopRow
Dim regRows
'OptionVal is a variable that stores the worksheet from another part of the
code
'OptoinVal does work

Worksheets(OptionVal).Activate

regTopRow = ActiveSheet.Row
regRows = ActiveSheet.Rows.Count

The error that is returned is a:
run-time error '438'
Object Doesn't support this Property or Method.

I am assuming that I don't have the correct 'reference' set.

Basically I am just trying to activate the indicated sheet, move to the
last record then move back up 3 rows and insert a new row... the last row is
a "totals line" that keeps a running total and I want the new records
inserted above that record.

Thanks for any help.
--
Thanks,
Gabriel