Processing extended transactions in client-server system

Extended business transactions are processed in a client-server system in a manner which allows processing initiated by a client to be interrupted before the transaction is complete and later resumedby the same or another client from the point of interruption. This is achieved by storing state information indicative of the progress of the transaction in a repository in association with an end-user identifier. When the end-user communicates his identifier via a client to the server for a second time, processing of the transaction can be resumed on the basis of the stored state.