Select Sections and SectionGroups

I have problem. I don't know how to better explain it.
OK, I'll start with section structure:

Section 1
SectionGroup
Section 2 (invisible)
Section 3 (optional)
SectionGroupEnd
Section 4

I have other sections too.

What I want to do is select "SectionGroup" when "Section 3" is selected. For now SectionGroup gets selected only partially (thus leaving "Section 2" unselected).

I tried to create .onSelChange function to check if "Section 3" is selected and if it is select "SectionGrop" as well.

  !include Sections.nsh

  Function .onSelChange

    !insertmacro SectionFlagIsSet "Section 3" SF_SELECTED set notset

    set:

      !insertmacro SelectSection SectionGroup

    notset:

  FunctionEnd

It didn't work. Can someone tell me what I am doing wrong?

"Section 3" is not a Section index define, but the Section caption right?
You define Section index constants like so:
Section "Section 3" Sec3
SectionGroup "My Group" SecGroup1

${Sec3} and ${SecGroup1} will contain the section indexes for those sections which you can use with all the Section instructions and macros.

Also make sure you place that Function below all your Sections.

Your code should look something like this:

  !include Sections.nsh

  Function .onSelChange

    !insertmacro SectionFlagIsSet ${Section3} SF_SELECTED set notset

    set:

      !insertmacro SelectSection ${SectionGroup}

    notset:

  FunctionEnd

-Stu

I didn't make myself clear for the first time, sorry for that.

It was meant as section index, I just wanted to make it more simple in this post.

I tried to put it into code like this: ${Index}, Index, "Index", ${"Index"}. None of them worked for me.

--Text deleted by user--

I had to put function below all sections, I skiped that in Your reply.

Thanks.

But now I can't unselect my section or section group...

Also you probably know this but SF_SELECTED -> ${SF_SELECTED}
To sort that out you'd probably have to check if the SectionGroup us selected first and then skip the code if it is.

-Stu

Thanks, it works (I checked if SectionGroup is partially selected)

Thank You for time You dedicated to me.