title: DateDiff if SSRS unless NULL
body: <p>So, I am trying to get a DateDiff to work, but only if one of the items is not null.  I have </p>
  
  <pre><code>=DateDiff("d",Today,Fields!Seller_Approval_Date.Value)
  </code></pre>
  
  <p>but if Seller_approval_date is null, I want it to display a N/A. </p>
  
  <p>I want it to display kind of the following, but I want it to display a difference in today's day and the displayed date:</p>
  
  <p><img src="https://i.stack.imgur.com/0nKsP.png" alt="Display error"></p>