Top => user_in_conf When were users in what conferences?

Notes:

Name Type Index Null? Default
userid varchar(250) (pk) No '' FK user_info

cnum int(11) (pk) No '0' FK confs

lastin datetime NULL date/time user was "last in" this conference

Name	Type	Index	Null?	Default
userid	varchar(250)	(pk)	No	''	FK user_info
cnum	int(11)	(pk)	No	'0'	FK confs
lastin	datetime			NULL	date/time user was "last in" this conference