title: SSRS IIF expression
body: <p>In my SSRS report I want PolDiscountPerc textbox from my query to make blank when PolStockCode in a row is empty or empty string, however if PolStockCode contains a value then format PolDiscountPerc textbox to display it as a percentage.</p>
  
  <pre><code>=IIF(IsNothing(Fields!PolStockCode.Value) or Fields!PolStockCode.Value is "", "",(Format(Fields!PolDiscountPerc.Value, "0.00") &amp; "%"))
  </code></pre>
  
  <p>The problem with following query is that it either does nothing or sets the textbox to blank for every row in the table despite the fact that most of them do contain the PolStockCode. Where have i gone wrong?</p>