Thanks for your instant reply, but i've still some questions: what secure prolems would occur during the process of logging if the forum provide the XML-RPC interface? as i found that many software provide this kinda XML-RPC interface, such as some BLOG programs(some could even publish contents via client software), how could they solve the secure issue?
the weblink hereunder is for your reference.
http://www.blogger.com/developers/api/documentation20.html
http://www.blogger.com/
http://www.pjhome.net/article.asp?id=420
i believe the prodigy-boRg- have ways to solve this.