title: Crystal Reports if-then-else selection based on parameter
body: <p>I have this crystal report, and I want to be able to use it to display every person in the table or display only those who owe money.</p>
  
  <p>The parameter is called displayAll and is a boolean.
  Basically I want this</p>
  
  <pre><code>if displayAll Then
     Show every person
  else
     Show only When Balance is below 0
  </code></pre>
  
  <p>How can I do this?</p>