title: Microsoft SQL Reporting Services conditional formatting OR expression issue
body: <p>I've been playing with MS Reporting services for the past few weeks in order to automate our "job status" reporting. <strong>I've been asked to highlight cells which are left blank or 0</strong>, so we can pick them up quicker.</p>
  
  <p>Take the "<em>Enquiry Ref</em>" columns on the below image. It'll only be any of the following:</p>
  
  <ul>
  <li>A Reference number</li>
  <li>Blank</li>
  <li>A number 0</li>
  </ul>
  
  <p><img src="https://i.stack.imgur.com/cSSrr.png" alt="Reporting services"></p>
  
  <p>I have tried the following:</p>
  
  <pre><code>//This highlights the cells with 0
  =IIF(Fields!EnquiryRef.Value = "0", "Yellow", "No Color")
  
  //This highlights the cells which are blank
  =IIF(Fields!EnquiryRef.Value = "", "Yellow", "No Color")
  
  //This seems to highlight neither of the two
  =IIF(Fields!EnquiryRef.Value = "0" OR Fields!EnquiryRef.Value = "", "Yellow", "No Color")
  </code></pre>
  
  <p>I can't seem to find an expression that covers both 0's and blanks.</p>