OverlayManager allows you to manage multiple Overlays (and Overlay subclasses like Panel, Dialog, SimpleDialog and Tooltip) on the same page, giving focus and z-index supremacy to the focused overlay and providing you with event hooks to respond to focus and blur of your overlays with your own scripts.
Use the buttons below to show and hide the overlays in this example's OverlayManager group. Click within differnt overlays and drag them around to get a sense for how OverlayManager provides a light, operating-system-like feel to the interaction.