On your silverlight sample pages You are using OptionsPanel. Here is the code in App.xaml:

 <LinearGradientBrush x:Key="BorderBackgroundBrush" StartPoint="0.0, 0.0" EndPoint="0.0, 1.0">
<GradientStop Color="#FFFFFFFF" Offset="0"/>
<GradientStop Color="#e0e2e8" Offset="1"/>
</LinearGradientBrush>


<LinearGradientBrush x:Key="GradientBorderBrush" StartPoint="0.0, 0.0" EndPoint="0.0, 1.0">
<GradientStop Color="#FFFFFFFF" Offset="0"/>
<GradientStop Color="#FFD6D6D6" Offset="1"/>
</LinearGradientBrush>

<Style x:Key="BorderStyle" TargetType="Border">
<Setter Property="CornerRadius" Value="3"/>
<Setter Property="Background" Value="{StaticResource BorderBackgroundBrush}"/>
<Setter Property="BorderBrush" Value="{StaticResource GradientBorderBrush}"/>
<Setter Property="BorderThickness" Value="4"/>
<Setter Property="Effect">
<Setter.Value>
<DropShadowEffect Color="Black" BlurRadius="10" ShadowDepth="0" Opacity="0.6"></DropShadowEffect>
</Setter.Value>
</Setter>
</Style>


<Style x:Key="ScrollViewerStyle" TargetType="ScrollViewer">
<Setter Property="BorderBrush" Value="Transparent" />
<Setter Property="Background" Value="Transparent" />
<Setter Property="VerticalScrollBarVisibility" Value="Auto" />
<Setter Property="HorizontalScrollBarVisibility" Value="Auto" />

</Style>
<Style TargetType="optPanel:OptionsPanel">
<Setter Property="Foreground" Value="#FF535F64" />
<Setter Property="FontSize" Value="11" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="optPanel:OptionsPanel">
<Border Style="{StaticResource BorderStyle}">
<Grid Background="White">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<!-- Header 2CBDF9-->
<Border x:Name="optPanel" Background="#28C5FF" Grid.ColumnSpan="2">
<TextBlock x:Name="textBlock" Text="{TemplateBinding HeaderText}" FontSize="12" Foreground="Black" TextWrapping="Wrap" Margin="5,3,26,5"/>
</Border>

<ToggleButton x:Name="btnClose" Content="X" IsChecked="True" Width="20" Height="20" FontSize="10" FontWeight="Normal"
IsThreeState="False" Grid.Column="1" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="0 3 3 3"/>

<ToggleButton x:Name="btnState" Content="-" IsChecked="True" Width="20" Height="20" FontSize="10" FontWeight="ExtraBold"
IsThreeState="False" Grid.Column="1" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="0 3 26 3"/>
<ScrollViewer x:Name="scrollContent" Style="{StaticResource ScrollViewerStyle}" Grid.Row="1" Grid.ColumnSpan="2">
<ItemsPresenter Grid.Row="1"/>
</ScrollViewer>
</Grid>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

And OptionsPanel.cs   code:

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Controls.Primitives;

namespace nDOCUSSL4
{
public class OptionsPanel : ItemsControl
{

ScrollViewer scrollContent;
public OptionsPanel()
{
base.DefaultStyleKey = typeof(OptionsPanel);
this.VerticalAlignment = System.Windows.VerticalAlignment.Top;
this.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
Loaded += new RoutedEventHandler(CustomPanel_Loaded);
}

void CustomPanel_Loaded(object sender, RoutedEventArgs e)
{
this.UpdateLayout();
var rootElement = VisualTreeHelper.GetChild(this, 0) as Border;/*kada ovde izbaci grešku znači da si stavio na xaml stranici da je visibility=collapsed*/
var winHandle = rootElement.FindName("optPanel") as Border;
var btnState = rootElement.FindName("btnState") as ToggleButton;
scrollContent = rootElement.FindName("scrollContent") as ScrollViewer;

winHandle.MouseMove += new MouseEventHandler(winHandle_MouseMove);
winHandle.MouseLeftButtonDown += new MouseButtonEventHandler(winHandle_MouseLeftButtonDown);
winHandle.MouseLeftButtonUp += new MouseButtonEventHandler(winHandle_MouseLeftButtonUp);

btnState.Click += new RoutedEventHandler(btnState_Click);

this.UpdateLayout();
GeneralTransform objGeneralTransform = this.TransformToVisual(this.Parent as FrameworkElement);
Point point = objGeneralTransform.Transform(new Point(0, 0));
tTranslate.X = point.X;
tTranslate.Y = point.Y;
this.Margin = new Thickness(0);
this.VerticalAlignment = System.Windows.VerticalAlignment.Top;
this.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
this.RenderTransform = tTranslate;
}

void btnState_Click(object sender, RoutedEventArgs e)
{
var btnState = (ToggleButton)sender;
scrollContent.Visibility = btnState.IsChecked.Value ? System.Windows.Visibility.Visible : System.Windows.Visibility.Collapsed;
btnState.Content = btnState.IsChecked.Value ? "-" : "+";
}

void btnClose_Click(object sender, RoutedEventArgs e)
{
    /*
       I get the feeling that I should write somethig here to close OptionsPanel, but what?
    */
}

#region Moving
TranslateTransform tTranslate = new TranslateTransform();
Point borderP;
Point currentP;
double maxMarginLeft;
double maxMarginTop;
bool dragOn = false;
private void winHandle_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
var c = sender as System.Windows.FrameworkElement;
dragOn = true;
this.Opacity *= 0.5;
borderP = e.GetPosition(sender as Border);
c.CaptureMouse();

maxMarginLeft = (this.Parent as FrameworkElement).ActualWidth - this.ActualWidth;
maxMarginTop = (this.Parent as FrameworkElement).ActualHeight - this.ActualHeight;
}

private void winHandle_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (dragOn)
{
var c = sender as System.Windows.FrameworkElement;
this.Opacity = 1;
c.ReleaseMouseCapture();
dragOn = false;
}
}

private void winHandle_MouseMove(object sender, MouseEventArgs e)
{
if (dragOn)
{
currentP = e.GetPosition(sender as Border);
var x = tTranslate.X + currentP.X - borderP.X;
var y = tTranslate.Y + currentP.Y - borderP.Y;

if (x < 0)
x = 0;
if (y < 0)
y = 0;
if (x > maxMarginLeft)
x = maxMarginLeft;
if (y > maxMarginTop)
y = maxMarginTop;
tTranslate.X = x;
tTranslate.Y = y;
}
}
#endregion

#region Dependency Properties
public static DependencyProperty HeaderProperty = DependencyProperty.Register(
"HeaderText", typeof(string), typeof(OptionsPanel), null);


public string HeaderText
{
get { return (string)GetValue(HeaderProperty); }
set { SetValue(HeaderProperty, value); }
}

#endregion

}
}

As you may have noticed I have added X button and click event

But I don't know how to close it? What is the code?

Regards, Marko.