How to remove the border in Coding4Fun MessagePrompt - windows-phone-7

Question

I followed this example to display my usercontrol inside Coding4Fun MessagePrompt.
http://windowsphonegeek.com/articles/Creating-a-Windows-Phone-7-Trial-Application-Adding-Buy-Now-Functionality
When the Home icon at the bottom of the page is clicked I open MessagePromt which has my UserControl with two buttons as shown in image below.
But for some reason there appears this light white border, I am unable to determine from where it is coming.
Note: I have set border Transparent and 0 thickness for my usercontorl and all controls inside it.
I just want to show the blue panel and no white border and it's width is 300 as what it is seen.
Does any one has any idea?

Answer 1

I got help from "Eric Fleck - Microsoft" on apphub forums. Here's his solution:
<phone:PhoneApplicationPage
...
xmlns:c4f="clr-namespace:Coding4Fun.Phone.Controls;assembly=Coding4Fun.Phone.Controls">
<phone:PhoneApplicationPage.Resources>
<ControlTemplate x:Key="MsgPropmtNoBorder" TargetType="c4f:MessagePrompt">
<Grid VerticalAlignment="Stretch">
<Rectangle Fill="{StaticResource TransparentBrush}" />
<Border VerticalAlignment="Top"
Margin="10"
Background="{TemplateBinding Background}"
BorderThickness="0"
BorderBrush="{StaticResource PhoneForegroundBrush}">
<StackPanel Margin="10">
<TextBlock
Text="{TemplateBinding Title}"
Margin="0,-10,-25,10"
FontSize="30"
TextWrapping="Wrap" FontFamily="Segoe WP Light" />
<ContentPresenter Content="{TemplateBinding Body}" />
<StackPanel
Margin="0,10,0,0"
Name="actionButtonArea"
Orientation="Horizontal"
HorizontalAlignment="Center" />
</StackPanel>
</Border>
</Grid>
</ControlTemplate>
</phone:PhoneApplicationPage.Resources>
MessagePrompt prompt = new MessagePrompt();
prompt.Body = new WPUC();
prompt.ActionPopUpButtons.Clear();
prompt.Overlay = new SolidColorBrush(Color.FromArgb(155, 41, 41, 41));
prompt.Template = (ControlTemplate)this.Resources["MsgPropmtNoBorder"];
prompt.Show();
Here's the resultant popup:

Answer 2

I played a bit with the MessagePrompt control, it couldn't found any way to disable or hide the border. It's a shadow kind of effect in MessagePrompt control to provide a popup like appearance.
However, Eventhough you cannot remove it, you can reduce it's effect by setting the Width property of the MessagePrompt equal to your actual blue UserControl ( 300 in this case).