title: How to choose which WIX dialog to show OnExit based on condition
body: <p>I have two WIX dialogs in my setup project</p>
  
  <p>Final form which is to be shown when installer terminates with status 'success'</p>
  
  <pre><code>&lt;Dialog Id="FinishedForm"&gt;
     ...
  &lt;/Dialog&gt;
  </code></pre>
  
  <p>and page to show several slides about our Product.</p>
  
  <pre><code>&lt;Dialog Id="IntroductionTourPage"&gt;
     ...
     &lt;Control Id="SkipTourButton" Type="PushButton"&gt;
        &lt;Publish Event="NewDialog" Value="FinishedForm"&gt;1&lt;/Publish&gt;
     &lt;/Control&gt;
     ...
  &lt;/Dialog&gt;
  </code></pre>
  
  <p>I want IntroductionTourPage is only to be shown after product is installed(not upgraded or removed), but I do not know how to do that. I tried</p>
  
  <pre><code>&lt;InstallUISequence&gt;
      &lt;Show Dialog="FinishedForm" OnExit="success"&gt;Condition&lt;/Show&gt;
      &lt;Show Dialog="IntroductionTourPage" OnExit="success"&gt;NOT Condition&lt;/Show&gt;
  &lt;/InstallUISequence&gt;
  </code></pre>
  
  <p>but it is not valid in Wix so it this approach failed. Then I tried</p>
  
  <pre><code>&lt;InstallUISequence&gt;
      &lt;Show Dialog="FinishedForm" Sequence="1"&gt;Condition&lt;/Show&gt;
      &lt;Show Dialog="IntroductionTourPage" Sequence="2"&gt;NOT Condition&lt;/Show&gt;
  &lt;/InstallUISequence&gt;
  </code></pre>
  
  <p>it didn't work. I tried then</p>
  
  <pre><code>&lt;InstallUISequence&gt;
      &lt;Show Dialog="FinishedForm" OnExit="success"/&gt;
      &lt;Show Dialog="IntroductionTourPage" Before="FinishedForm"&gt;Condition&lt;/Show&gt;
  &lt;/InstallUISequence&gt;
  </code></pre>
  
  <p>but it is not valid in Wix as well.</p>
  
  <p>Now I want to try smth like: </p>
  
  <pre><code>&lt;InstallUISequence&gt;
      &lt;Custom Action="CA_ChooseAndShowDialogBasedOnCondition" OnExit="success"/&gt;
  &lt;/InstallUISequence&gt;
  </code></pre>
  
  <p>but I can't find any example how to show Wix dialogs from CA. </p>
  
  <p>Any ideas?</p>
  
  <p>Thanks in advance,
  Andriy</p>