bardzo słabo Panie hebel

<phone:PhoneApplicationPage
    x:Class="NaszaSuperAplikacja.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">


   <phone:PhoneApplicationPage.Resources>
        <DataTemplate x:Key="LongListTemplate">
            <StackPanel>
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition></ColumnDefinition>
                        <ColumnDefinition></ColumnDefinition>
                    </Grid.ColumnDefinitions>
                    <TextBlock Text="" Grid.Row="3"/>
                    <TextBlock Text="{Binding Imie}" HorizontalAlignment="Left" Grid.Row="0" Grid.Column="0"/>
                    <TextBlock Text="{Binding Nazwisko}" HorizontalAlignment="Left" Grid.Row="0" Grid.Column="1"/>
                    <TextBlock Text="{Binding Stanowisko}" HorizontalAlignment="Left" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2"/>
                    <TextBlock Text="{Binding PESEL}" HorizontalAlignment="Left" Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="2"/>
                </Grid>
            </StackPanel>
        </DataTemplate>
    </phone:PhoneApplicationPage.Resources>


    <Grid x:Name="LayoutRoot" Background="Transparent" Grid.Row="3">
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>


        <phone:LongListSelector x:Name="LongList" Grid.Row="0"
                                ItemTemplate="{StaticResource LongListTemplate}" Margin="10,0,-10,0" Tap="KierowcaTap"/>


    </Grid>





</phone:PhoneApplicationPage>