Underneath

[Jeanne A. E. DeVoto]

At 12:27 AM +0300 8/27/2016, Richmond wrote:
>This doesn't seem to work because this cycles through ALL the 
>controls, and, of course,
>the object being dragged is also a control.


Ah. Forgot about that. You'll need to add a condition:

     if within(control x, the mouseLoc) \
        AND ("P" is not in the short name of control x)
        AND (the ID of the target is not the ID of control x) then