title: Enable animation with blend using property binding condition
body: <p>I am working with blend 4,
  I am trying to play some StoryBoard using ControlStoryBoardAction with the contidion: if a specific Border Element in my UC has greater width then 250.</p>
  
  <p>I set the next configuration:
  <img src="https://i.stack.imgur.com/KGs2g.png" alt="Set data binding"></p>
  
  <p><img src="https://i.stack.imgur.com/Zm5Cb.png" alt="Config ControlStoryBoardAction "></p>
  
  <p>And when I run my application I am getting the following error:</p>
  
  <p>LeftOperand of type "OpeningViewModel" cannot be used with operator "GreaterThan".
    Source=Microsoft.Expression.Interactions</p>
  
  <p>What I am doing wrong?
  How can I launch StoryBoard with element property condition?</p>