Restaurant and Waiter project! (WPF - Windows Mobile)

<UserControl xmlns:my1="clr-namespace:System.Windows.Controls;assembly=PresentationFramework"  xmlns:my="clr-namespace:System.Windows.Controls;assembly=PresentationFramework"  x:Class="Restaurant.ProductTreeUserControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
	mc:Ignorable="d"
    xmlns:My="clr-namespace:Restaurant"
    xmlns:local="clr-namespace:Restaurant"
             Loaded="UserControl_Loaded"
    d:DesignWidth="640" d:DesignHeight="480" FontFamily="Ariral" FontSize="14" Foreground="White" >
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="40"/>
        </Grid.RowDefinitions>
        <Grid Height="70">
    		<TextBlock Text="Group:" Foreground="White" HorizontalAlignment="Left" VerticalAlignment="Bottom" Margin="131,0,0,0" Height="30" TextAlignment="Left"/>
    		<ComboBox Margin="181,33,109,7" x:Name="cmbGroup" SelectionChanged="cmbGroup_SelectionChanged" Width="350" />
    	</Grid>
        <local:SortableListView Grid.Row="1" x:Name="ProductsGridView" Height="Auto"  Margin="10,10,10,5" 
                             Background="{x:Null}"  BorderBrush="{x:Null}"
            ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.VerticalScrollBarVisibility="Auto"
            VirtualizingStackPanel.IsVirtualizing="True" ScrollViewer.CanContentScroll="True"
            SelectionMode="Single" IsSynchronizedWithCurrentItem="True"
                           ItemContainerStyle="{DynamicResource RestaurantListViewItemStyleSmall}"
                           Style="{DynamicResource RestaurantEditListViewStyle}" FontSize="12">
            <local:SortableListView.View >
                <GridView AllowsColumnReorder="False">
                    <GridViewColumn Width="4" HeaderContainerStyle="{DynamicResource FirstColumnGridViewColumnHeader}" CellTemplate="{StaticResource EmptyColumnTemplate}"/>
                    <local:SortListViewColumn Header="Product ID" DisplayMemberBinding="{Binding Path=ProductID}" SortProperty="ProductID" Width="100" SortStyle="RestaurantDataGridViewColumnHeader" HeaderContainerStyle="{DynamicResource RestaurantDataGridViewColumnHeader}"/>
                    <local:SortListViewColumn Header="Product Name" DisplayMemberBinding="{Binding Path=ProductName}" SortProperty="ProductName" Width="298" SortStyle="RestaurantDataGridViewColumnHeader" HeaderContainerStyle="{DynamicResource RestaurantDataGridViewColumnHeader}"/>
                    <local:SortListViewColumn Header="Unit" DisplayMemberBinding="{Binding Path=UnitName}" SortProperty="UnitName" Width="110" SortStyle="RestaurantDataGridViewColumnHeader" HeaderContainerStyle="{DynamicResource RestaurantDataGridViewColumnHeader}"/>
                    <local:SortListViewColumn Header="Price" DisplayMemberBinding="{Binding Path=Price}" SortProperty="Price" Width="100" SortStyle="RestaurantDataGridViewColumnHeader" HeaderContainerStyle="{DynamicResource RestaurantDataGridViewColumnHeader}"/>
                    <GridViewColumn Width="4" HeaderContainerStyle="{DynamicResource LastColumnGridViewColumnHeader}" CellTemplate="{StaticResource EmptyColumnTemplate}"/>
                </GridView>
            </local:SortableListView.View>
        </local:SortableListView>
        <Button Grid.Row="2" HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="White" FontSize="10" Width="120" Height="26" x:Name="btnPrint" Style="{DynamicResource BlueButtonStyle}" Content="Print Menu" Click="btnPrint_Click"/>
    </Grid>
</UserControl>