TCMDrag = packed record
  Msg: Cardinal;
  DragMessage: TDragMessage;
  Reserved1: Byte;
  Reserved2: Word;
  DragRec: PDragRec;
  Result: Longint;
end;

struct TCMDrag {
  unsigned Msg;
  TDragMessage DragMessage;
  Byte Reserved1;
  Word Reserved2;
  PDragRec DragRec;
  Longint Result;
};