title: ssrs len() with the datasetname
body: <p>I have the following issue :</p>
  <p>This works:</p>
  <blockquote>
  <p><code>LEN(Fields!LIBEL_FONCTION.Value) = 0</code></p>
  </blockquote>
  <p>This or this , do not work :</p>
  <blockquote>
  <p><code>LEN(Fields!LIBEL_FONCTION.Value, &quot;DataSetDirigeants&quot;) = 0</code></p>
  <p><code>(LEN(First(Fields!LIBEL_FONCTION.Value, &quot;DataSetDirigeants&quot;)) = 0</code></p>
  </blockquote>
  <p>Why and is there a way to deal with this SSRS limitation (if it is a limitation)?</p>
  <p>Thanks</p>