The customer presses the Connect button (2240) on the customer terminal (1230). By this, a connection request to an operator terminal is notified to an operator terminal (1210) via the push sharing server (2100). On receiving this notification, the operator terminal (1210) changes the Respond button (2310) to the Incoming button. When the operator presses the Respond button (2310) on the operator web page (2300), the push sharing server (2100) transmits a difference notification command to the operator terminal (1210), and the operator terminal displays the same web page as the web page on the customer terminals (1230).