The usability of web applications today often suffers from the page-based medium’s lack of intrinsic support for hierarchical dialog sequences mirroring the parent-child relationships between dialog boxes in window-based user interfaces. For multi-channel applications, an additional challenge lies in reconciling the device-independent business logic with the device-specific interaction patterns necessitated by different clients’ input/output capabilities.We therefore present a graphical Dialog Flow Notation that allows the specification of nestable dialog sequences for different presentation channels. These specifications serve as input for a Dialog Control Framework that controls the dialog flows of complex web applications.