POWER OF ATTORNEY

                                                                    Exhibit 24.1

STATE OF          Illinois                  )
                                            )  SS
COUNTY OF         Cook                      )

      KNOW ALL MEN BY THESE PRESENTS that Joseph B. McAdams, having an address
at Hot Springs, Arkansas, has made, constituted and appointed and BY THESE
PRESENTS, does make, constitute and appoint Thomas P. Heneghan and Michael B.
Berman, or either of them, having an address at Two North Riverside Plaza,
Chicago, Illinois 60606, his true and lawful Attorney-in-Fact for him and in his
name, place and stead to sign and execute in any and all capacities this Annual
Report on Form 10-K and any or all amendments to this Annual Report on Form
10-K, and to file the same with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commission, giving and
granting unto each of such, Attorney-in-Fact, full power and authority to do and
perform each and every act and thing, requisite and necessary to be done in and
about the premises, as fully, to all intents and purposes as he might or could
do if personally present at the doing thereof, with full power of substitution
and revocation, hereby ratifying and confirming all that each of such
Attorney-in-Fact or his substitutes shall lawfully do or cause to be done by
virtue hereof.

      This power of Attorney shall remain in full force and effect until
terminated by the undersigned through the instrumentality of a signed writing.

      IN WITNESS WHEREOF, Joseph B. McAdams, has hereunto, set his hand this
1st day of March, 2005.

                                                  /s/ Joseph B. McAdams
                                                  --------------------------
                                                  Joseph B. McAdams

      I, Jennifer L. Usher, a Notary Public in and for said County in the State
aforesaid, do hereby certify that Joseph B. McAdams, personally know to me to be
the same person whose name is subscribed to the foregoing instrument appeared
before me this day in person and acknowledged that he signed and delivered said
instrument as his own free voluntary act for the uses and purposes therein set
forth.

      Given under my hand and notarial seal this 1st day of March, 2005.

                                                  /s/ Jennifer L. Usher
                                                  ---------------------------
                                                  (Notary Public)

My Commission Expires:

      01/06/07