TDBPlanner header item spanning multiple days - how to read header?

Hi, I have a TDBPlanner with a PlannerItem that spans multiple days (Delphi 7). The item correctly shows in the header of the resource but of course this doesn't stop a user creating a booking during the days that the header booking applies.

When creating an appointment item by double clicking in the planner, I want to prompt the user with a warning. How do I detect that there is an item in the resource header?

I've tried DBPlanner1.PositionProps[DBPlanner1.SelPosition].Collection.Count but that throws an error.

Laurence Bevan
New Zealand

You can detect in code if there is already an all-day (header) item in a specific position (day) of the Planner with the code:

planner.Items.HasHeaderItem(pos): boolean