A system comprising a display provided with zones, a token, a proximity sensor for detecting the proximity of a token to one zone and a processor to register in a memory an association upon the detection of the proximity of the token to the zone. The association is logged as a set of data comprising the data of which a representation is made on the zone in the proximity of which the token has been brought. The processor is programmed to update a log file with the logged association. The processor performs an operation in accordance with the content of the log file.