Variation in different mobile devices with different capabilities and interaction modalities as well as changing user context in nomadic applications, poses huge challenges to the design of user interfaces. To avoid multiple designs for each device or modality, it is almost a must to employ a model-based approach. In this short paper, we present a new dialog model for multimodal interaction together with an advanced control model, which can either be used for direct modeling by an interface designer or in conjunction with higher level models.