Hide the template elements in code-behind file - windows-phone-7

Question

I have a LongListHeaderTemplate that consists of a list and a button. You will see how are they distributed in the code below. My problem is that I need sometimes hide button in code-behind file. How I can do that?!
XAML:
<toolkit:LongListSelector Grid.Row="1" ListHeader="{Binding EpsLaterItems}" IsFlatList="True" ItemsSource="{Binding EpsItems}" x:Name="EPS" SelectionChanged="EPS_SelectionChanged_1">
<toolkit:LongListSelector.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding ImageUrl, Converter={StaticResource BmpConverter}}" Width="100" Height="100" VerticalAlignment="Top" Margin="0,10,18,0"/>
<StackPanel Margin="0,0,0,20" Width="300">
<TextBlock Text="{Binding Date, ConverterCulture=ru-RU, StringFormat=f}"
FontSize="22" FontWeight="Bold" Foreground="#FFD65B2D" />
<TextBlock Text="{Binding Title}" TextWrapping="Wrap" FontSize="22" Foreground="Aqua" />
</StackPanel>
</StackPanel>
</DataTemplate>
</toolkit:LongListSelector.ItemTemplate>
<toolkit:LongListSelector.ListHeaderTemplate>
<DataTemplate>
<StackPanel>
<ListBox x:Name="listbox1" ItemsSource="{Binding}" ScrollViewer.VerticalScrollBarVisibility="Disabled" >
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding ImageUrl, Converter={StaticResource BmpConverter}}" Width="100" Height="100" VerticalAlignment="Top" Margin="0,10,18,0"/>
<StackPanel Margin="0,0,0,20" Width="300">
<TextBlock Text="{Binding Date, ConverterCulture=ru-RU, StringFormat=f}"
FontSize="22" FontWeight="Bold" Foreground="#FFD65B2D" />
<TextBlock Text="{Binding Title}" TextWrapping="Wrap" FontSize="22" Foreground="Aqua" />
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<Button x:Name="footerEpsLater" Content="more..."
FontSize="30" Foreground="SteelBlue" Style="{StaticResource StyleForButton}" BorderBrush="#FFFF2121"/>
</StackPanel>
</DataTemplate>
</toolkit:LongListSelector.ListHeaderTemplate>
<toolkit:LongListSelector.ListFooterTemplate>
<DataTemplate>
<Button Content="more..." FontSize="30" Foreground="SteelBlue" Click="footerEPS_Click_1" Style="{StaticResource StyleForButton}"/>
</DataTemplate>
</toolkit:LongListSelector.ListFooterTemplate>
</toolkit:LongListSelector>
If i do like this footerEpsLater.Visibility = Visibility.Collapsed; I get the error: footerEpsLater does not exist in this context