Recover the value of an object if the key match

Question

I would like to recover the value of a key in an object if the key matches with the condition

here is the condition :

var lang = 'EN'

here is the condition :

var translate : {EN: "name_EN", FR: "name_FR", NL: "name_NL"} 

if the key corresponds to the variable lang I would like to recover the corresponding value.

here -> "name_EN"