[PD] first exercise with data structures

[Patrice Colet]

----- Mail original -----
> De: "Alexandre Torres Porres" <porres at gmail.com>

> I've just started tweaking with it to see if I finally learn it, but
> it's crashing a lot!!! I'm just changing arguments in the struct
> object and it crashes... I clicl on GOP box and it crashes... things
> like that.

Every scalars have to be removed before modifying [struct] otherwise it crashes