how to diff the open and shared Algorithm when use WEP encryption(NOT manually)

[shili]

dear all,
   when i choose to use WEP encryption, and choose the  Algorithm is
shared, i need to write auth_alg=SHARED Manually, and when i choose the
Algorithm is open, i need to write auth_alg=OPEN Manually, I want to ask
is there any way to get the Algorithm? then i can change the wpa_gui's
code, when it is the WEP encryption, I can write auth_alg= OPEN or
auth_alg=SHARED to the wpa_suppliant.conf by SET_NETWORK command,so is
there any way to diff the Algorithm? 
   BTW:i also can change the driver code.