Help with setting up if then conditions

Yet again I find myself needing a bit of help.

Here’s what I’ve done:

I’ve set up a multi record section editor and have included a pull down list field with a list of categories. IE: “book, CD, Magazine, etc. (BTW, what’s the difference between a simple pull down list and a multi value pull down list?)

Here’s what I’m trying to do:

On my details page, if the group_code of the particular record is “book” then I would like to display field “A”, if it’s “CD” I’d like to display field “B”, if it’s “magazine” I’d like to display field “C”, and if it’s none of those I’d like to display field “D”.

I’ve looked around on the forum but I’m still a bit confused.

Thanks,

Jerry Kornbluth