LIMITED POWER OF ATTORNEY

          The undersigned hereby constitutes and appoints each of Luke
Valentino, Marge Bajzek and Debra Cherry, with full power to each of them to act
alone, as his or her true and lawful attorney-in-fact to:

          (1)  execute and file in the name and on behalf of the undersigned
               Forms 3, 4 and 5 pursuant to Section 16(a) of the Securities
               Exchange Act of 1934 and the rules thereunder;

          (2)  do and perform any and all acts for and on behalf of the
               undersigned which may be necessary or desirable to complete the
               execution of any such Form 3, 4 or 5 and the timely filing of
               such form with the United States Securities and Exchange
               Commission, the NASDAQ Stock Market, or otherwise; and

          (3)  take any other action of any type whatsoever in connection with
               the foregoing which such attorney-in-fact in his or her sole
               discretion determines may be of benefit to, in the best interest
               of, or legally required by, the undersigned, it being understood
               that the documents executed by such attorney-in-fact on behalf of
               the undersigned pursuant to the Power of Attorney shall be in
               such form and shall contain such terms and conditions as such
               attorney-in-fact may approve in his or her discretion.

          Until such time as the undersigned is no longer subject to the
obligations imposed by Section 16, the undersigned hereby grants to each such
attorney-in-fact full power and authority to do and perform each and every act
and thing whatsoever which such attorney-in-fact in his or her sole discretion
determines to be necessary or appropriate to be done in the exercise of any of
the rights and powers herein granted, with full power of substitution or
resubstitution, hereby ratifying and confirming all that such attorney-in-fact,
or his or her substitute or substitutes, shall lawfully do or cause to be done
by virtue of this Power of Attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in
such capacity at the request of the undersigned, are not assuming any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934 and shall have no liability with respect thereto.

          IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of this 16 day of October, 2018.



                                        /s/ William L. Transier
                                        ------------------------------
                                        William L. Transier