 
Set Variable result to 
 
label: start
Display Dialog: start, wait for dialog to return (modal)
 
if Variable result Equals CANCEL
  Terminate Installation
end
 
label: preReq
Display Dialog: preReq, wait for dialog to return (modal)
Comment: MessageBox: result, $result$
if Variable result Equals CANCEL
  Terminate Installation
end
if Variable result Equals PREVIOUS
  GoTo Label: start
end
if Variable result Equals BTNDETAILS
  Display Dialog: details, wait for dialog to return (modal)
  GoTo Label: preReq
end
Display Dialog: end, wait for dialog to return (modal)
 
