title: How to set Unassigned Value to Option Set CRM 2015 using Script or Business Rule
body: <p>I have an Parent Option Set call "Conveyance Type" as per image : 
  <a href="https://i.stack.imgur.com/Geszq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Geszq.png" alt="enter image description here"></a></p>
  
  <p>Default is nothing select. If user Select "Elevator" then I am going to show the following Option Set called : "Capacity" and it's look like this. 
  <a href="https://i.stack.imgur.com/EXsKW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EXsKW.png" alt="enter image description here"></a></p>
  
  <p>So let say use select "2000 lbs" .  Then after user select "Escalator" from "Conveyance Type" so at that time from Business rule I am going to hide the "Capacity" option set. </p>
  
  <p>And again I select "Elevator" from the "Conveyance Type" I am going to show "Capacity" option set.  But issue is I am geting last selected value. </p>
  
  <p>I have try <code>Xrm.Page.Data.Entity.Attributes.Get("new_capacity").setValue(null);</code> Using JavaScript. </p>