Cell Value Changed Event in Datagrid

Mar 12, 2010 at 12:10 PM
hello friends
i am new to wpf and using datagrid (WPFToolKit)
what i want is to raise an event when cell value is modified or changed and want to access modified value
what i have done is 
CellStyle="{StaticResource RightAlignedCellStyle}" 
Header="Qty." Binding="{Binding Path=QTY}" 
Width="100" > 
        <Style TargetType="{x:Type TextBox}">
           <EventSetter Event="LostFocus" Handler="Qty_LostFocus" />

Private Sub Qty_LostFocus(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs)
        If Not IsDBNull(DtDetail.Compute("sum(Amount)", "")) Then
            GROSSAMOUNT = DtDetail.Compute("sum(Amount)", "")
        End If
End Sub

this code raise event QTY_LostFocus, but i could not get modified value in it. if i try to access value as DataGrid1.Items(0)("ID"), it returns me old value. 
Moreover i have binded this datagrid with datatable. this new value is not reflected in datatable also. 
Could any one plz help me about this
Thanks in advance