title: Issue with Sum on a colum in Rdlc Report
body: <p>I have a rdlc report.</p>
  
  <p>Supposing there are two columns</p>
  
  <pre><code>   Trval      Status
     10000        YES
     20000        YES
     30000        NO
  
  Total= 30000
  </code></pre>
  
  <p>Currently i am using this expression to get the above:</p>
  
  <pre><code>=Sum(IIf(Fields!Lead_Status.Value = "YES", Fields!TrValRange.Value, 0))
  </code></pre>
  
  <p>Assuming it will add the  TrValRange to the result each time its a YES. But in case where
  there are no Status=YES it says 0. However when there are rows with <code>Status=YES</code> it gives <code>ERROR</code> .</p>
  
  <p>Also TrValRange is a string field do we need some sort of conversion here to Sum? Any suggestions.</p>
  
  <p>Thank you</p>