// This function call is the same as Listing 4, only now I specify a function 
// (ErrorFunction) to call if the server encounters an error, as well as a context value:
objServer.Bounce(InValue, DisplayFunction, ErrorFunction, ("tracer");

// The "context value" is accessed this way:
function DisplayFunction(objReturn) {
    // Here is the return value:
    alert(objReturn.return_value);
    // Here is the "context value":
    alert(objReturn.context);
}