EXHIBIT 3.28

                          CERTIFICATE OF INCORPORATION
                                       OF
                                 MCS/AZ, INC.

     FIRST: The name of the Corporation is MCS/AZ, Inc. (hereinafter the
"Corporation").

     SECOND: The address of the registered office of the Corporation in the
State of Delaware is 1209 Orange Street, in the City of Wilmington, County of
New Castle. The name of its registered agent at that address is The Corporation
Trust Company.

     THIRD: The purpose of the Corporation is to engage in any lawful act or
activity for which a corporation may be organized under the General Corporation
Law of the State of Delaware as set forth in Title 8 of the Delaware Code (the
"GCL").

     FOURTH: The total number of shares of stock which the Corporation shall
have authority to issue is 1000 shares of Common Stock, each having a par value
of one penny ($.01).

     FIFTH: The name and mailing address of the Sole Incorporator is as follows:


                                 Mary E. Keogh
                                 P.O. Box 636
                                 Wilmington, DE 19899

     SIXTH: The following provisions are inserted for the management of the
business and the conduct of the affairs of the Corporation, and for further
definition, limitation and regulation of the powers of the Corporation and of
its directors and stockholders:

          (1) The business and affairs of the Corporation shall be managed by
     or under the direction of the Board of Directors.

                                                           STATE OF DELAWARE
                                                           SECRETARY OF STATE
                                                        DIVISION OF CORPORATIONS
                                                       FILED 09:00 AM 10/29/1999
                                                          991459933 - 3118714


     EIGHTH: The Corporation reserves the right to amend, alter, change or
repeal any provision contained in this Certificate of Incorporation, in the
manner now or hereafter prescribed by statute, and all rights conferred upon
stockholders herein are granted subject to this reservation.

     I, THE UNDERSIGNED, being the Sole Incorporator hereinbefore named, for
the purpose of forming a corporation pursuant to the GCL, do make this
Certificate, hereby declaring and certifying that this is my act and deed and
the facts herein stated are true, and accordingly have hereunto set my hand
this 29th day of October, 1999.

                                             /s/ Mary E. Keogh
                                             ------------------------
                                             Mary E. Keogh
                                             Sole Incorporator


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