Custom form page before wizardform - how to quit directly?

I created an autorun.exe with inno setup, with a custom form page. Now when I click on exit or close, the inno setup welcome page appears and starts to install. How can I set the exit and close button (bisystemmenu) to quit f开发者_如何转开发rom setup, or prevent wizardform to initialize?

It depends where you're showing the form from. If in InitializeSetup() then just return false after the window is closed.