Get content of control inside listbox item when it was clicked - windows-phone-7

Question

I have a ItemTemplate like this
<ListBox>
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Button Grid.Row="0">
<Button.Template>
<ControlTemplate>
<Border BorderBrush="AntiqueWhite" BorderThickness="1">
<StackPanel Orientation="Horizontal" Background="Gray" Width="465">
<Image Margin="2,0,10,0" Source="{Binding StateImage}" Stretch="None"/>
<TextBlock Name="txt" Text="{Binding DateLabel}"/>
</StackPanel>
</Border>
</ControlTemplate>
</Button.Template>
<Custom:Interaction.Triggers>
<Custom:EventTrigger EventName="Click">
<mx:EventToCommand Command="{Binding VisibilityListboxCommand}"
CommandParameter="{Binding EementName=txt, Path=Text}"
/>
</Custom:EventTrigger>
</Custom:Interaction.Triggers>
</Button>
<ListBox Grid.Column="1" ItemsSource="{Binding WhatsonList, Mode=OneWay}">
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderBrush="Gray" BorderThickness="0,0,0,1" Padding="0,0,0,10">
<Grid Margin="0,10,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100"/>
<ColumnDefinition Width="360"/>
</Grid.ColumnDefinitions>
<StackPanel Grid.Column="0">
<Button>
.....
</Button>
<CheckBox Template="{StaticResource CheckboxImageTemplate}" Margin="0,5,0,0"/>
</StackPanel>
<ListBox Grid.Column="1">
.....
</ListBox>
</Grid>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
When I click on button inside listboxitem datatemplate I want to get content of textblock txt to find out what listbox item was clicked to trace back index in the List(model) that listbox bind from.
But from commandparameter I cannot get anything because there are many textblock named txt I think.
Please help me !

Answer 1

A better way to solve this is by binding the CommandParameter to 'thing' in the DataContext of the item like this:
<Custom:Interaction.Triggers>
<Custom:EventTrigger EventName="Click">
<mx:EventToCommand Command="{Binding VisibilityListboxCommand}"
CommandParameter="{Binding}" />
</Custom:EventTrigger>
</Custom:Interaction.Triggers>
This way the binding does not rely on a particular control being present and having a specific name.