Example:
This example comes from Greg Liefs "SUPPRESSING MOUSE AND KEYBOARD EVENTS".

begin
   Enabled := False ;
   Form2.Show ;
   Form2.Update ;
   For c := 1 to 1000 do begin
   Form2.LMDLabelX.Caption := IntToStr(c);
   Application.ProcessMessages ;
   end ;
   Form2.Close;
   Enabled := True ;
   SetFocus ;
end ;