Where is StackPanel in IronPython / .Net 4?

[Ian Hobson]

Hi All,

According to this page

http://msdn.microsoft.com/en-us/library/system.windows.controls.stackpanel.aspx

StackPanel is in the System.Windows.Controls Namespace

When I try and set up a reference to that Namespace I get a "Could not 
add reference to assembly
System.Windows.Controls" error on the line that reads

clr.AddReference('System.Windows.Controls')

Can anyone shed light on what is going wrong?

Many thanks

Ian