where to put StateChanged triggers?

Where do we put the StateChanged trigger from expressionblend.codeplex.com ?

<i:Interaction.Triggers>
  <sam:StateChanged Completed="True" StateName="BeforeUnloaded"> 
   <... /> 
  </sam:StateChanged> 
</i:Interaction.Triggers>

the above code i tried gave me a compile error say开发者_运维知识库ing A value of type 'StateChanged' cannot be added to a collection or dictionary of type 'TriggerCollection'.

In blend, i added the assembly but when i click the New button in the Trigger properties panel, the assembly or the StateChanged trigger doesn't show up in dialog...

the documentation only gives a description and no syntax example

thanks

ok i've solved my problems.. i converted the expression sample source code to WPF4 and it shows up and works in blend now... thanks...