windows phone 7 hide left-hand line in ExpandView

To hide the left border:

1. In Codeplex, download the Toolkit Source & Sample (under Other Available Downloads) and open the PhoneToolkit solution
2. In the project Microsoft.Phone.Controls.Toolkit, open the folder named Themes, and edit Generic.xaml
3. Look for this in Generic.xaml (should be at line 1522)
   

                               <Line x:Name="Line" Grid.Row="1" Grid.Column="1" 

                                     Grid.RowSpan="2" 

                                     HorizontalAlignment="Left" 

                                     Stroke="{StaticResource PhoneSubtleBrush}"  

                                     StrokeThickness="3" X1="0" Y1="0" X2="0" Y2="1" 

                                     Stretch="Fill"/> 

4. Replace PhoneSubtleBrush with TransparentBrush
5. Rebuild the Microsoft.Phone.Controls.Toolkit project 
6. Build and run the PhoneToolkitSample app to test it
7. In your project, delete the reference to the installed Microsoft.Phone.Controls.Toolkit, and add a reference to the Microsoft.Phone.Controls.Toolkit.dll that you built in step 5