Planner prevent adding a defaultItem

After select a few cells in the TTMSFNCPLanner for the web, i show an popup . In the popup you can fill in an edit with random text. When the popup is closed the text is added to the planner item (typeTTMSFNCPlannerItem) title. This works well. But every time when i select one or more cells the default item also is added. How can i prevent that the default item will be added. Her are som settings:

This line belongs to the topic: Here are some settings: Interaction.MouseInsertMode := pmimAfterSelection; and MediPlanner.DefaultItem.Enabled := False;

When Interaction.MouseInsertMode is set to pmimAfterSelection, an item is created when releasing the mouse after selecting a range. It's unclear exactly how you start the dialog?