Cascading radcomboboxes in a detailtable that is in batch edit mode

For the last few days, I've tried, with no success to achieve something that should be doable.

Cascading radcomboboxes in a detailtable that is in batch edit.

I have a Radgrid bound to a sqldatasource with a GridTableView in batch edit.

Column 1, is a gridtemplate column with a radcombobox (combo1), bound to a sqldatasource. AllowCustomText="true"

Column 2 is a gridtemplate column with a radcombobox (combo2) that needs the selected item in combo1 and then rebind or rebuild the list of items based upon the selection of combo1. Again, autotext=True

Column3 is a gridtemplate textbox that will be populated based upon a query of combo1 and combo2 selected values (or text - doesn't matter).

I know you can't set autopostback=true because of the batch edit.

I've tried figuring out a client side rebinding of combo2, but no joy.

Can anyone PLEASE provide some example of this?

thanks in advance.

John