PDF (adobe.com)

Create rollovers with hotspots

Use the drag-and-drop rollover method to attach a disjoint rollover effect to a hotspot. The target area must be defined by a slice. Rollover effects are applied to hotspots the same way that they are to slices.

Note: A hotspot can trigger only a disjoint rollover. It cannot be the target of a rollover coming from another hotspot or slice.

After you create a disjoint rollover with a hotspot, the connecting blue line remains visible only while the hotspot is selected.