A server-client system includes a client terminal having a telephone function, and a server apparatus on a network. The terminal displays telephone number display screen data received form the server apparatus, and transmits, to the server apparatus, designation information indicating a telephone number position in the display screen, which is designated by a user. The server apparatus transmits designated telephone number outgoing call data to the terminal based on the designation information. The terminal makes an outgoing call in accordance with the telephone number outgoing call data received from the server apparatus.