Patent ID: 7115035

Claim:
A network game system having a server apparatus and a plurality of client apparatuses each connected to said server apparatus via a network, said server apparatus comprising: a server message receiver that receives messages from each of said plurality of client apparatuses; a server message transmitter that transmits messages on progress of a game including the messages received by said server message receiver to each of said plurality of client apparatuses via the network; and a specific information transmitter that transmits specific information when said server message transmitter transmits a specific message, the specific information indicating that the transmitted message is the specific message, each of said plurality of client apparatuses comprising: a message input device that inputs a desired message on the progress of the game according to a user's operation; a client message transmitter that transmits the messages input from said message input device via said network to cause said server message receiver to receive the messages; a client message receiver that receives messages transmitted from said server message transmitter; a specific information receiver that receives the specific information transmitted from said specific information transmitter; a message display device that displays messages received by said client message receiver within a chat window while scrolling the messages sequentially; and a display controller that controls scroll-display displayed by said message display device such that the received messages are sequentially scrolled to erase an oldest message from the chat window, and display of the message corresponding to specific information received by said specific information receiver is prevented from being erased from the chat window by the scrolling a until a predetermined condition is satisfied, when the specific message is the oldest message and otherwise would be erased by scrolling in response to displaying a new message.