fix a bug such that driver can recursively extract forms now
fix a bug such that driver can recursively extract forms now

cmu-db/db-webcrawler,cmu-db/cmdbac,cmu-db/cmdbac,cmu-db/cmdbac,cmu-db/db-webcrawler,cmu-db/db-webcrawler,cmu-db/cmdbac,cmu-db/db-webcrawler,cmu-db/cmdbac,cmu-db/db-webcrawler