FlexRow.Position Property
Indicates the line number currently pointing.
The line number is the line number at the time you refer to the Position property. After getting the FlexRow object, the row numbers may change due to FlexView row operations.
If the InvalidState property is $TRUE, referencing the Position property raises the exception EXT-12.
If MovePrev points before the first line, it will be FlexView.PrevEndPosition (-900).
If MoveNext points to the next in the last row, it will be FlexView.NextEndPosition (-901).