anchor.diff:  
   parse_register_contact_expire(Header, Contact) when is_record(Header, keylist),
   						    is_record(Contact, contact) ->
  -    ExpireHeader = sipheader:expire(Header),
  +    ExpireHeader = sipheader:expires(Header),
       parse_register_contact_expire(ExpireHeader, Contact).
   
       
  
positive.code: 
      %% get expire value from request header only once, this will speed up the calls to
      %% parse_register_contact_expire/2 that are done for each Locations entry
      ExpireHeader = sipheader:expire(RequestHeader),
      F = fun(Location) ->
  		process_non_wildcard_contact(LogTag, SipUser, Location,
  					     RequestCallId, RequestCSeq, ExpireHeader)
  
negative.code: %% Function: parse_register_contact_expire(Header, Contact)
  %%           parse_register_contact_expire(ExpireHeader, Contact)
  %%           Header  = keylist record(), the request headers
  %%           ExpireHeader = sipheader:expires(Header) return value
  %%           Contact = contact record(), a contact entry from a request
  %% Descrip.: determine the expire time supplied for a contact in a SIP
  %%           REGISTER request
  