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                                                                    EXHIBIT 10.1






                               September 26, 2000


Community Bank, N.A.
5790 Widewaters Parkway
Dewitt, New York 13214

Dear Ladies and Gentlemen:

                  The undersigned is a shareholder of The Citizens National Bank
of Malone ("Citizens") and is the owner of shares of common stock of Citizens
("Citizens Common Stock").

                  Citizens, Community Bank System, Inc. ("CBSI"), and Community
Bank, N.A. ("Community") are considering the adoption and/or execution of an
Agreement and Plan of Merger (the "Merger Agreement"), providing for certain
transactions pursuant to which Citizens would be merged with and into Community
(the "Merger"). The execution of the Merger Agreement is subject in the case of
Community to the execution and delivery of this letter agreement (this
"Agreement"). In consideration of the substantial expenses that Community will
incur in connection with the Merger and in order to induce Community to execute
the Merger Agreement and to proceed to incur such expenses, the undersigned
agrees and undertakes, in his capacity as a shareholder of Citizens as follows:

                  1. Voting of Shares. The undersigned will vote or cause to be
voted for approval and adoption of the Merger Agreement all the shares of
Citizens Common Stock the undersigned is entitled to vote with respect thereto,
unless by a two-thirds vote the Board of Directors of Citizens votes to
terminate the Merger Agreement and accept a superior agreement based upon their
fiduciary duties.

                  2. No Transfer of Shares. The undersigned will not effect any
transfer or other disposition (except by operation of law) of any of the
undersigned's shares of Citizens Common Stock until Citizens' shareholders have
voted to approve and adopt the Merger or until the Merger Agreement has been
terminated pursuant to its terms, except for any transfer mandated by law or
court order. In the case of any transfer of operation of law or otherwise, this
Agreement shall be binding upon and inure to the benefit of the transferee to
the extent permitted by law. Any transfer or other disposition in violation of
the terms of this paragraph 2 shall be null and void.

                  3. Affiliates Obligated. The undersigned acknowledges and
agrees that the provisions of paragraphs 1 and 2 hereof shall also apply to
shares of Citizens Common Stock
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owned by (a) his or her spouse, (b) any of his or her relatives or relatives of
his or her spouse occupying his or her home, (c) any trust or estate in which he
or she, his or her spouse, or any such relative owns at least a 10% beneficial
interest or of which any of them serves as trustee, executor or in any similar
capacity, and (d) any corporation or other organization in which the
undersigned, any affiliate of the undersigned, his or her spouse, or any such
relative owns at least 10% of any class of equity securities or of the equity
interest.

                  4. Related Actions. In the capacity described in this
Agreement, the undersigned shall take or cause to be taken all action necessary
or desirable on the undersigned's part so as to permit completion of the Merger
at the earliest possible date and shall not take, or cause or to the best of the
undersigned's ability permit to be taken, any action which would substantially
impair the prospects of completing the Merger pursuant to the Merger Agreement.

                  5. Covenants under Rule 145. The undersigned has been advised
that the issuance of shares of common stock of CBSI ("CBSI Common Shares") to
the undersigned pursuant to the Merger will be registered under the Securities
Act of 1933, as amended (the "Securities Act"), pursuant to a registration
statement on Form S-4 (the "S-4 Registration Statement"). The undersigned has
also been advised that the undersigned will or may be deemed an "affiliate" of
Citizens at the time the Merger is submitted to a vote of the shareholders of
Citizens. Accordingly, the undersigned may not sell or otherwise dispose of any
CBSI Common Shares except in accordance with Rule 145(d) promulgated under the
Securities Act.

                  Generally speaking, this means that, to the extent that the
undersigned is an "affiliate", in any given three month period the undersigned
may not sell or otherwise dispose of a number of shares of CBSI Common Shares
which exceeds the greater of (i) 1% of the outstanding number of CBSI Common
Shares (or approximately 69,900 CBSI Common Shares) or (ii) the average weekly
trading volume during the four weeks preceding the sale. In addition, any CBSI
Common Shares must be sold in a brokers' transaction or in a direct transaction
with a market maker. In other words, there is no limitation on you selling CBSI
Common Shares unless you seek to sell more than 69,900 shares in a three month
period. Further, the restrictions discussed in this paragraph are only
applicable for a one year period following the closing of the Merger.

                  6. Remedies. The undersigned acknowledges and agrees that any
remedy at law for breach of the foregoing provisions shall be inadequate and
that, in addition to any other relief which may be available, Community shall be
entitled to temporary and permanent injunctive relieve without the necessity of
proving monetary damages.

                  IN WITNESS WHEREOF, the undersigned has executed this
Agreement as of the date of first written.

                                    Very truly yours,



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Accepted and agreed to as of
the date first above written:

COMMUNITY BANK, N.A.


By:______________________


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