How to make a menu in OnInspectorGUI


I Have a little problem, I don’t know how to make a custom inspector for my function.
Let me explain you with a little draw to see exactly what i mean.

Note that Menu Deroulant is a Scroll down menu.
And when I click on Add, it create an other ‘Box’ with “Fleche, Choix and Revert” in The ‘Big Box’


Thx for reply but i found by myself how to do this thing, you have to use Property Drawers.
It’s not easy to understand but when you’ve got it you can do a lot of things.
here is a complete description of Property Drawers (must have unity 4) : Property Drawers

Thanks i will tag this post as Resolved.