created PHONEBK.DAT
added   SMITH                555-0101         Boston          
added   JONES                555-0202         Chicago         
added   ADAMS                555-0303         Denver          
added   SMYTHE               555-0404         Austin          
duplicate smith
ADAMS                555-0303         Denver          
JONES                555-0202         Chicago         
SMITH                555-0101         Boston          
SMYTHE               555-0404         Austin          
-- 4 entries
JONES                555-0202         Chicago         
changed JONES                555-7777         Chicago         
JONES                555-7777         Chicago         
deleted Adams
not found: Adams
SMITH                555-0101         Boston          
SMYTHE               555-0404         Austin          
3 entries
opened PHONEBK.DAT
JONES                555-7777         Chicago         
SMITH                555-0101         Boston          
SMYTHE               555-0404         Austin          
-- 3 entries
added   ZED                  555-0000         Zurich          
ZED                  555-0000         Zurich          
no names from Q
