Function onCustomPage
  ; replace $2's current value with the top of the stack
  Exch $2
  ; save $1's value
  Push $1
  
  ; Show our custom InstOpts pages.
  StrCmp $2 "B" 0 +2 ; second page
    ; if value of $R9 from last page is
    ; "don't show" then don't show
    StrCmp $R9 "don't show" Done 

  Push "$TEMP\myini$0.ini"
  CallInstDll "$TEMP\instopts.dll" dialog
  Pop $1
  StrCmp $1 "success" ReadData
    SetErrors
    StrCmp $1 "back" ReadData
      ; Something else - abort the installer.
      Call Cleanup
      Quit

ReadData:
  StrCmp $2 "A" 0 Done
    ; if this is the first page
    ReadINIStr $3 "$TEMP\myini$2.ini" "Field 8" State
    StrCmp $3 "" Show DontShow
DontShow:
		StrCpy $R9 "don't show"
		Goto done
Show:
		StrCpy $R9 ""

Done:
  ; get the original value of $1 back
  Pop $1
  ; get the original value of $2 back
  Pop $2
FunctionEnd