add comments for direction, fix index in strB fetch (maybe)
add comments for direction, fix index in strB fetch (maybe)

chenm001/connectal,chenm001/connectal,hanw/connectal,csail-csg/connectal,csail-csg/connectal,8l/connectal,cambridgehackers/connectal,csail-csg/connectal,chenm001/connectal,cambridgehackers/connectal,8l/connectal,8l/connectal,8l/connectal,8l/connectal,csail-csg/connectal,cambridgehackers/connectal,cambridgehackers/connectal,cambridgehackers/connectal,hanw/connectal,csail-csg/connectal,hanw/connectal,hanw/connectal,hanw/connectal,chenm001/connectal,chenm001/connectal