How to access a listbox inside a panorama datatemplate?

How to access a listbox inside a panorama datatemplate?

I want to access a control inside a datatemplate, my code:
<phone:Panorama.ItemTemplate>
<DataTemplate>
<ScrollViewer Width="800"
HorizontalContentAlignment="Left" Margin="0,50,0,0">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ListBox x:Name="list_of_images">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<Image Width="300" Height="300"
Source="{Binding}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ListBox>
How can I access the listbox and list_of_images in codebehind?