ListboxItem design for Multiresolution App windows phone

Question

I want to develop app which is targeting to Multi resolution Device i Windows Phone(i.e. : 480*800 to 1080*1920) this is my code for list box

<ListBox x:Name="LstContact">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Border BorderBrush="#cbc6c0"
                                    BorderThickness="0,0,0,2"
                                    Margin="10">
                                <Grid >
                                    <TextBlock Text="{Binding FirstName}"
                                               Foreground="Black"
                                               FontSize="22"
                                               Margin="10" />
                                </Grid>
                            </Border>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>

And output should be like this

please help to that

Answer 1

It is Silverlight, so just put something like Width="480" to your Border and you are done.