how to acess on controls inside of stackpanel in windows phone7?

i design page bellow code.

<ScrollViewer VerticalScrollBarVisibility="Visible" Grid.Row="1" x:Name="svProduct">
            <StackPanel>
                <ItemsControl  x:Name="lstSearchResult" ItemsSource="{Binding Path=PIProductList}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Width="480" Style="{Binding CellStyle}" Orientation="Horizontal" VerticalAlignment="Center" Height="50" >
                                <TextBlock Foreground="Black" FontSize="20" Width="320" FontFamily="Tahoma" Margin="10,0,0,0" Text="{Binding Title}" VerticalAlignment="Center" TextWrapping="Wrap"></TextBlock>
                                <Button Name="btnBookmark" Click="btnBookmark_Click" Tag="开发者_如何学运维{Binding}" Background="Transparent">
                                    <Button.Content>
                                        <Image Source="/Images/bookmarks_red.png" Width="33" Height="30" VerticalAlignment="Top" Margin="-15"></Image>
                                    </Button.Content>
                                </Button>
                                <Button BorderThickness="0" x:Name="btnSubmit" Click="btnSubmit_Click" Background="Transparent" Tag="{Binding}" >
                                    <Button.Content>
                                        <Image Name="ram" Source="/Images/blue_arrow.png" Width="40" Height="40" VerticalAlignment="Top" Margin="-15"></Image>
                                    </Button.Content>
                                </Button>
                            </StackPanel>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </StackPanel>
        </ScrollViewer>

i want to access for btnBookmark visuble false .

can't access btnBookmark.Visibility=Visibility.collapsed

how to do this?

please help to me...........

---

The best way I know to do this is to create a Visiblity property on your item ViewModel (the one that is bound to each row in your ItemsControl) and toggle that value based on the changes to each item, presumably via the toggle button in each row. I don't know of a good way to "loop and look" for these internal controls. You're much better off using the existing data binding infrastructure to manage this for you.