Datagrid current row number is the same as the dataset row number?

[Alpha]

I'm working on a Window based application. I have 2 textboxes and a datagrid
on a form. The textboxes are databind to the same datasource as datagrid. I
want to use the following to update the dataset but I am not suer if the
datagrid's current row number does corresponds to the row number in the
dataset table that I want to update. Appreciate it if someone can give me
answer to this.
Thanks, Alpha

private void txtLastOdometer _Validated(obje ct sender, System.EventArg s e)
{
dsMaintDued.Tab les["MaintenanceDue d"].Rows[dgMaintDued.Cur rentRowIndex]["LastOdometerRe ading"] = txtLastOdometer .Text.ToString( );
}

private void dtpLastService_ Validated(objec t sender, System.EventArg s e)
{
dsMaintDued.Tab les["MaintenanceDue d"].Rows[dgMaintDued.Cur rentRowIndex]["LastOdometerDa te"] = dtpLastService. Value.ToString( );
}