Callback function with an InstallOptions page

I've created a custom page using the InstallOptions plugin. I'm trying to attach a custom callback function to the page, but I'm having problems getting the callback to work. (Basically, I want to stay on my custom page until certain conditions are met.)

Nothing I've tried has made the custom callback function work. The callback works fine using the pre-defined MUI screens, but not in my custom page. I haven't been able to find any good examples of how to use custom callbacks on an InstallOptions page.

Look at the function 'CusFuncB' in the following example

!include "MUI.nsh"

; MUI Settings

!define MUI_ABORTWARNING

!define MUI_ICON "${NSISDIR}\Contrib\Graphics\Icons\blue.ico"

!define MUI_PAGE_HEADER_TEXT $Header1

!define MUI_Page_HEADER_SUBTEXT $Header2

!define MUI_DIRECTORYPAGE_TEXT_DESTINATION "Select directory:"

!define MUI_WELCOMEPAGE_TITLE "Welcome to the ${PRODUCT_NAME} Version ${PRODUCT_VERSION} setup Wizard"



; Welcome page

!insertmacro MUI_PAGE_WELCOME

; Customer Number page

Page custom CustomPageA

; Directory page

!define MUI_PAGE_CUSTOMFUNCTION_PRE GetCusNumber

!define MUI_PAGE_CUSTOMFUNCTION_LEAVE VerifyMyDir

!define MUI_DIRECTORYPAGE_TEXT_TOP "Install Package blah"

!insertmacro MUI_PAGE_DIRECTORY



; Custom Page:



; ********  HERE'S THE FUNCTION THAT DOESN'T WORK *******

!define MUI_PAGE_CUSTOMFUNCTION_LEAVE CusFuncB

Page custom CustomPageB

; Finish page

!insertmacro MUI_PAGE_FINISH



LangString TEXT_IO_TITLE ${LANG_ENGLISH} $Header1

LangString TEXT_IO_SUBTITLE ${LANG_ENGLISH} $Header2



Function CustomPageA

   !insertmacro MUI_HEADER_TEXT "$(TEXT_IO_TITLE)" "$(TEXT_IO_SUBTITLE)"

	!insertmacro MUI_INSTALLOPTIONS_DISPLAY "ioEnterNumber.ini"

   

FunctionEnd



Function CustomPageB

   !insertmacro MUI_HEADER_TEXT "$(TEXT_IO_TITLE)" "$(TEXT_IO_SUBTITLE)"

   !insertmacro MUI_INSTALLOPTIONS_DISPLAY "ioSelectLogo.ini"



FunctionEnd



Function CusFuncB

   ; some function - blah blah blah

FunctionEnd

Anyone out there have any tips/examples/etc.?

use

Page custom CustomPageEnter CustomPageLeave

sometimes it's very useful to have a look at the docs ...

I was so focused at looking all over the MUI and InstallOptions docs that I completely missed the Page command of the regular NSIS help files!

Thanks for your help Comm@nder21!