7/3/2014 7:59 AM
To my beloved k. [probably short for kedves = dear] aunt [or elder sister] Carolin and uncle [or elder brother] Jóska [dim. of Joseph], from Jenö [usually "translated" as Eugene, although they're technically unrelated]
J[ános]háza, Sep. 11, 1937
Stamp/printing: Rezsö [created as a Hungarianization of Rudolf] Molnár, watchmaker, jeweler, optician, and photography dealership, Jánosháza.
(Oh, and the photo paper is Agfa-Lupex brand.)
He's wearing a Bocskai suit (Bocskai öltöny), which was a fashion that developed between the world wars as an expression of national identity. It was originally intended as everyday wear, to replace the more generic Western suit-and-tie that was still normal in that more formal age, but as fashion became less and less formal, the Bocskai suit became more of a special-occasion outfit, worn for things like graduations, balls, and weddings. It's still in fashion -- my dad wore one to my wedding. You can rent them in Hungary, just like tuxedos here in the U.S.
My guess is that the photograph was taken at Jenö's graduation, probably from high school (gymnasium).