Get BoundColumn Data

[RN1]

A DataGrid displays records from a database. The Datagrid displays 13
columns (excluding the EditCommandColumn). In some of the rows, only
the first 8 cells will show data & the last 5 will be blank (because
they are nulls in the database).

Now suppose the DataGrid is in the editable mode (note that all
columns are BoundColumns). I enter some data in the 10th textbox
(which is blank & whose index is 9). Now when I click the Update
button (In the EditCommandColumn), then

CType(ea.Item.Cells(9).Controls(0), TextBox).Text

retrieves a blank string. It doesn't retrieve the data I entered in
the 10th textbox when the DataGrid was is the editable mode.

Can someone please tell me what could be the problem?