how to get AD Referrals

[bjleiliang]

i have three AD server,each domain like this
test.com(main domain)
part1.test.com(sub domain) part2.test.com(sub domain)

i want to write a small ldapviewer application,but when i use 'ldap_search' function to search AD test.com, the function return '1',i use ldap_set_option(FLDAP, LDAP_OPT_REFERRALS, LDAP_OPT_OFF); the 'ldap_search' function run success.but how can i list the sub domain AD's struct?
i need all the AD's struct to displayed within a tree
like this:

test.com
-rootou
--dept1
--dept2
-DC=part1
--dept1
-DC=part2
--dept1