silverlight - Error about UserControl not supported in WPF in Expression Blend 2 -

I created only one Silverlight 2 app in Visual Studio, but when I go to open it in Blend, / P>

UserControl is not supported in the Windows Presentation Foundation (WPF) project

This is the XAML code

  & lt; UserControl x: Class = "MyFirstApp.Page" xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns: x = "http://schemas.microsoft.com/winfx/ 2006 / Xaml "width =" 400 "height =" 300 "& gt; & Lt; Grid X: Name = "Layouts" background = "White" & gt; & Lt; StackPanel Orientation = "Vertical" & gt; & Lt; Text box x: name = "myTextBox" fontSystem = "60" /> & Lt; Button content = "click me" FontSize = "60" click = "button_click" /> & Lt; / StackPanel & gt; & Lt; / Grid & gt; & Lt; / UserControl & gt;  

Am I missing a reference or something?

You need to install