SCHEDULE 14A
                                 (Rule 14a-101)

                     INFORMATION REQUIRED IN PROXY STATEMENT

                            SCHEDULE 14A INFORMATION
           Proxy Statement Pursuant to Section 14(a) of the Securities
                      Exchange Act of 1934 (Amendment No. )

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[ ]      Preliminary Proxy Statement        [ ] Confidential, for use of the
                                                Commission Only (as permitted by
                                                Rule 14a6(e)(2))
[ ]      Definitive Proxy Statement
[ ]      Definitive Additional Materials
[X]      Soliciting Material pursuant to Rule 14a-12

                            Advance Financial Bancorp
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                (Name of Registrant as Specified in Its Charter)

    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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         (2)     Aggregate number of securities to which transaction applies:
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         (3)     Per  unit  price  or other  underlying  value  of  transaction
                 computed pursuant to Exchange Act Rule 0-11(c):
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         (4)     Proposed maximum aggregate value of transaction:

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[ ]      Fee paid previously with preliminary materials.

[ ]      Check box if  any  part of the fee is offset as  provided  by  Exchange
         Act Rule  0-11(a)(2)  and identify the filing for which the  offsetting
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April 18, 2001                               Advance Financial Bancorp
                                             Stephen M. Gagliardi
                                             (304) 737-3531


                                             Ohio State Financial Services, Inc.
                                             Jon Letzkus
                                             (740) 635-0764



                          ADVANCE FINANCIAL BANCORP AND
               OHIO STATE FINANCIAL SERVICES, INC. ANNOUNCE MERGER


         April 18, 2001:  Advance  Financial Bancorp (NASDAQ Small Cap Market --
"AFBC"),  Wellsburg, West Virginia and Ohio State Financial Services, Inc. ("OTC
BB -- "OSFS"),  Bridgeport,  Ohio  announced the signing on April 18, 2001 of an
Agreement  and Plan of  Merger,  whereby  Advance  Financial  Bancorp  ("Advance
Financial")  will  acquire  all of the  outstanding  common  stock of Ohio State
Financial Services,  Inc. ("OSFS") for $16.00 per share in cash. This represents
an  aggregate  acquisition  price of  approximately  $8  million.  The merger is
subject to  approval  by the  stockholders  of OSFS and  receipt  of  regulatory
approvals.  Advance Financial is a holding company that owns all of the stock of
Advance Financial  Savings Bank ("Advance Bank"),  and OSFS is a holding company
that  owns  all  of  the  stock  of  Bridgeport  Savings  and  Loan  Association
("Bridgeport S&LA"). Pursuant to the Agreement,  Bridgeport S&LA will merge with
and into Advance Bank.

         Advance  Financial  Savings Bank, the  subsidiary of Advance  Financial
Bancorp,  is a  federally-chartered  FDIC-insured  savings bank founded in 1935.
Advance Financial Savings Bank operates from its main office in Wellsburg,  West
Virginia and from two full-service  branch offices in Follansbee,  West Virginia
and Wintersville,  Ohio. Bridgeport Savings and Loan Association, the subsidiary
of Ohio  State  Financial  Services,  Inc.,  is an  Ohio-chartered  FDIC-insured
savings and loan association.  Bridgeport  operates from its main office located
in  Bridgeport,  Ohio  and  from  one  full-service  branch  office  located  in
Shadyside, Ohio. Stephen M. Gagliardi,  President and Chief Executive Officer of
Advance Financial,  stated, "We are pleased to announce the acquisition of OSFS.
This will be a positive addition to the Company. Merging Bridgeport Savings into
Advance  will  permit  us to  offer  our  full  line of  financial  services  to
Bridgeport   Savings  customers  and  the  residents  and  businesses  in  their
communities. We expect the acquisition to enhance the value of the Company." Jon
Letzkus,  President and Chief Executive  Officer of OSFS said, "We are delighted
to become part of Advance  Financial  Savings  Bank, a local  community-oriented
financial  institution.  We believe the  transaction is in the best interests of
our stockholders,  customers and employees.  We believe this merger will provide
long-term  benefits for our customers." At December 31, 2000,  Advance had total
assets  and   stockholders'   equity  of  $161.8   million  and  $15.8  million,
respectively,  and OSFS had  total  assets  and  stockholders'  equity  of $33.1
million and $8.1 million, respectively.





         OSFS will be filing a proxy  statement  and  other  relevant  documents
concerning the merger with the Securities and Exchange  Commission  ("SEC").  WE
URGE  INVESTORS TO READ THE PROXY  STATEMENT  AND ANY OTHER  RELEVANT  DOCUMENTS
FILED WITH THE SEC BECAUSE THEY CONTAIN IMPORTANT INFORMATION. Investors will be
able to obtain the documents free of charge at the SEC's  website,  www.sec.gov.
In  addition,  documents  filed with the SEC by OSFS will be  available  free of
charge from its Corporate Secretary at 435 Main Street, Bridgeport, Ohio, 43912,
telephone (740) 635-0764. Documents filed with the SEC by Advance Financial will
be available free of charge from the Corporate Secretary of Advance Financial at
1015 Commerce Street,  Wellsburg, WV 26070, telephone (304) 737-3531.  INVESTORS
SHOULD READ THE PROXY STATEMENT  CAREFULLY  BEFORE MAKING A DECISION  CONCERNING
THE MERGER.

         OSFS and its directors and officers may be deemed to be participants in
the  solicitation of proxies in connection with the upcoming  special meeting of
stockholders.  INFORMATION  ABOUT THE  PARTICIPANTS  MAY BE OBTAINED THROUGH THE
SEC'S WEBSITE FROM THE DEFINITIVE  PROXY MATERIALS FILED BY OSFS WITH THE SEC ON
MARCH 13, 2001.

         Statements  contained  in this news  release  which are not  historical
facts are  forward-looking  statements,  as that term is defined in the  Private
Securities Litigation Reform Act of 1995. Such forwarding-looking statements are
subject to risks and  uncertainties  which could cause actual  results to differ
materially  from those currently  anticipated due to a number of factors,  which
include, but are not limited to, factors discussed in documents filed by Advance
Financial  and OSFS with the  Securities  and Exchange  Commission  from time to
time.  Advance Financial and OSFS do not undertake,  and specifically  disclaim,
any obligation to publicly  release results of any revisions that may be made to
any forward-looking statements.