Custom Join Questions

How do I add a custom join question?  (Trying to combat spam without blocking china.)

I've tried searching the forum ...Quite honestly, I'm fed up.

Can anyone tell me what to do?

This may help with the security question.... http://www.boonex.com/forums/?action=goto&my_flags=1#topic/China-is-invading-help-me-with-form-field-validation.htm

but to be 100% honest....... block ALL of china. I didnt want to, but really there is no choice. I check my logs every day and trace the IP's. The ones that dont make it through the net are all from the same locations in china - its pure spam and its now blocked. my site is now 100% spam free since blocking china. : )

i have a module i am working on still, other things took precedence, i thought surely boonex would come up with a solution. they were notified that the bots were circumventing the join.php file and joining the site

the module i am working on requires a pin verification which is provided via a phone number that must be answered