Asterisk realtime LDAP

Any one know how to install module res_config_ldap.so in asterisk 1.6
I have done many way but got the same error:

i made “make menuselect” and saw in option “resouce modules” have XXX res_config_ldap
I think there is a problem with res_config_ldap.c file, so that it can’t build to res_config_ldap.so.
Can any one help me to solve that! thank you very much!