Problem with binding in WPF

[furqanms]

Hello,

I am new to WPF ,I am developing touch screen system using WPF. I am facing problem in Binding relative reference.

Here is my code :

<UserControl x:Class="uctlBr owser"
xmlns="http://schemas.microso ft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microso ft.com/winfx/2006/xaml" Width="300" Height="300">
<Grid Width="Auto" Height="Auto">
<ListBox Name="lstUICate gory" IsSynchronizedW ithCurrentItem=
"True"
ItemsSource="{B inding}" Margin="7,3,0,1 0">
<ListBox.ItemCo ntainerStyle>
<Style>
<Setter Property="Contr ol.Padding" Value="0"></Setter>
<Style.Triggers >
<Trigger Property="ListB oxItem.IsSelect ed" Value="True">
<Setter Property="ListB oxItem.Backgrou nd" Value="DarkRed"/>
</Trigger>
</Style.Triggers>
</Style>
</ListBox.ItemCon tainerStyle>
<ListBox.ItemTe mplate>
<DataTemplate >
<Grid Margin="0" Background="Whi te">
<Border Margin="5" BorderThickness ="1" BorderBrush="St eelBlue" CornerRadius="4 "

Background="{Bi nding RelativeSource= {RelativeSource Mode=FindAncest or, AncestorType={x :Type ListBoxItem}},
Path=Background
}"
>
<Grid Margin="3">
<Grid.RowDefini tions>
<RowDefinition> </RowDefinition>
<RowDefinition> </RowDefinition>
</Grid.RowDefinit ions>
<TextBlock FontWeight="Bol d" Text="{Binding Path=long_desc} "></TextBlock>
<TextBlock FontWeight="Bol d" Text="{Binding Path=type_id}"> </TextBlock>

</Grid>
</Border>
</Grid>
</DataTemplate>
</ListBox.ItemTem plate>
</ListBox>
</Grid>
</UserControl>



In this code at Backgroud Binding I am getting error :" AncestorType must be specified for RelativeSource in FindAncestor mode. "

So please help me to solve this problem

Thanking you

Regards