title: Change messages/texts at runtime (Inno Setup)
body: <p>In an innosetup script it is possible to define messages like this:</p>
  
  <pre><code>[Messages]
  WelcomeLabel2=This wizard will update [name] to version [name/ver]
  </code></pre>
  
  <p>Now I would like to change this message at runtime, like this:</p>
  
  <pre><code>procedure InitializeWizard;
  begin
      //this doesn't work        
      WelcomeLabel2=NEW MESSAGE 
  end;
  </code></pre>
  
  <p>What is the correct way to do this? I want to dynamically change the contents of the welcome page to display whether the setup is performing a new installation or update. Based on the existence of some executables in the installation directory.</p>