[NTG-context] times new roman, arial and courier fonts

Hello all, how to set times new roman as \rm, arial as \ss and courier as \tt? \usetypescriptfile[type-win] \usetypescript[times] \usetypescript[arial] \usetypescript[courier] \setupbodyfont[times,10pt] This code sets just \rm, but \ss and \tt are left as default latin modern font. Thank you, Marius