How to get the original value from a gridview edited column

How can I get the original value of an edited column in a gridview during the RowUpdating event?
The column in question is bound to a field named "Amount" and is an integer. It is the 3rd column in the grid after the command column and one other.
I have tried various variations of
Dim orig As String = e.OldValues.Item(2).ToString and Dim orig As String = e.OldValues.Item("Amount").ToString without success. (In VB please.)
Thanks