Prompting for a directory

[WhitedragonBC]

I have 2 different sections on the components page, if the user has section 2 selected i need to prompt them to enter a directory, but not if they only have section 1 selected.
I know how to use page directory and installoptions to prompt for a directory, but how do i make them only appear if the user has section 2 selected? Using "InstallOptions::dialog "$PLUGINSDIR\FDSDir.ini"" in the section does bring up the dialog, but all the buttons are greyed out and you cant do anything.
I searched and couldnt find the answer to this on the forums or the wiki.

[Afrow UK]

code:
!include Sections.nsh



!insertmacro MUI_PAGE_DIRECTORY



!define MUI_PAGE_CUSTOMFUNCTION_PRE Directory2Pre

!insertmacro MUI_PAGE_DIRECTORY



Section "Section 2" Sec2



SectionEnd



Function Directory2Pre

 SectionGetFlags ${Sec2} $R0

 IntOp $R0 $R0 & ${SF_SELECTED}

 StrCmp $R0 ${SF_SELECTED} +2

  Abort

FunctionEnd

-Stu