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  Parent.Perform(WM_SYSCOMMAND,SC_DRAGMOVE,0);					

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var
   oParent: twincontrol;
   fForm: tform;
begin
   oParent := Self;
   fForm := nil;
   while assigned(oParent) and (not assigned(fForm)) do
   begin
      if oParent is tform then
         fForm := (oParent as tform);
      oParent := oParent.Parent;
   end;
   if assigned(fForm) then
      fForm.Perform(WM_SYSCOMMAND,SC_DRAGMOVE,0);
end;