A method of requesting the execution of a function in a client computer system ("client") in a client-server environment, the function being applicable to a data object processed by a server computer system ("server"). The method comprises the prior steps of obtaining (S301) an interface of the object and selecting (S303, S305) a function from the interface. This method is characterized in that it comprises the following steps: determining (S307) the types of different results sent back as a result of the execution of the function, from result type identification information, encoded in the interface; selecting (S309) at least one desired result type from the result type identification information; generating (S311) a message invoking the function, the invoking message including a list of desired results, each item of the list indicating a selected type of result; sending (S313) the message invoking the function to the server.