title: SSRS Parameters IIF Expression
body: <p>I have two parameters 1 is called <code>DataAreaId</code> and is set to a value by the database behind the scenes (Dynamics AX). I have another parameter which is multi select called <code>Company</code>. Now I am trying to pass the parameter value from <code>DataAreaId</code> to <code>Company</code> based on a condition.</p>
  
  <p>If the <code>DataAreaId = "002"</code> then the default value for the <code>Company</code> parameter must be select all, if not then the company parameter must equal the <code>DataAreaId</code> parameter. I have tried this and other permutations but I am having no joy. I appreciate any support you can offer me.</p>
  
  <pre><code>=iif(Parameters!dataareaid.Value = "002", join(Parameters!company.Value,","),Parameters!dataareaid.Value)
  </code></pre>