roxy server; and in the case of the registration server 130, a program for the registration server). [0036] The above-mentioned programs each may be stored in the memory 302 or the external storage 303 in advance, or may be installed into the memory 302 or the external storage 303 using a storage medium such as a memory card, a flexible disk or a CD-ROM and a reader (not shown) of the medium, or u