Web applications are currently widespread thanks to cloud computing and optimization of rendering/Javascript engines. Associating distant interactions devices could enhance user experience for such applications or allow them to become more pervasive. Our project Miny (Multimodality Is Nice For You) intends to provide a framework to develop multimodal Web applications. We have implemented a middleware that allows developers to easily program communication between web application and distant interaction devices. We show on an example how we can associate dynamically interaction modalities at runtime thanks to reflexive properties of Javascript.