Title: "On variational principles (mostly smooth ones)."

Abstract: A less known smooth variational principle in separable Banach space will be presented and proved. It will be compared with other principles like Ekeland, Bourgain-Stegall, Borwein-Preiss, Deville-Godefroy-Zizler. An application for Gateaux differentiability of convex functions will be indicated.