to prevent unexpected http session timeouts on the web and enable reliable business processing on the web , a unit for notifying a user of timeouts of web and a unit for the user to change timeout intervals in the processing of web applications such as online shopping . the present invention includes an application system which provides application services via a network and clients which receive the application services via the network , in which the application system sends to the clients a program for generating a window which displays information about timeouts on web sessions of application services , and the clients display the window based on the program received .