Retrieving values from DataGrid row before update

[greenb]

I have an editable datagrid and need to retrieve the values of the cells
before they are changed by the user. I tried to read the text values from
the cells in
the ItemCommand event and the OnEdit event but they are always empty
strings.
Does anyone know the best way to do this?

All the other datagrid functionality is working correctly (edit, update,
delete, and paging).

Thanks for your help.