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                                                                      Exhibit 99

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.


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         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.