Read the example I posted.. the very last function has what you are looking for..
Code:
new iPlayerID = g_iMenuPlayers[g_iMenuPosition * MENU_PLAYERS + key]
new szUsername[32]
get_user_name( iPlayerID, szUsername, 31 )
client_print( id, print_chat, "You Picked Player: '%s'!", szUsername )
// do any command on iPlayerID, like:
set_user_noclip( iPlayerID, 1 )
@west: Sup man, I remember you..

starwars3 was fun, but now you gotta check out my ka_hockey!!