<PAGE>
                                                                   EXHIBIT 10.1

                                 PROMISSORY NOTE

$540,000.00                                            Laguna Hills, California
10.50%                                                           March 27, 1998


         FOR VALUE RECEIVED, the undersigned COMMERCE SECURITY BANCORP, INC., a
Delaware corporation, ("Borrower") hereby promises to pay to DARTMOUTH CAPITAL
GROUP, L.P., a Delaware limited partnership ("Lender"), or its order, in lawful
money of the United States of America, the sum of Five Hundred Forty Thousand
Dollars ($540,000.00) plus interest at the non-default rate of ten and one half
percent (10.50%) per annum on the unpaid balance, with principal and interest to
be paid as set forth below.

        1. PAYMENTS. The principal hereof shall be payable in eight (8) equal
installments of Sixty-Seven Thousand Five Hundred ($67,500), due on or before
the last banking day of each calendar quarter commencing June 30, 1998, in each
case together with all interest accrued and unpaid on the principal amount
outstanding as of immediately prior to such payment.

        2. DEFAULT-RATE INTEREST; COMPOUNDING OF INTEREST.  In the event any 
payment of principal and/or interest is not paid in full when due hereunder,
including upon acceleration pursuant to Section 3 below, interest shall accrue
from and after the due date for such payment at the rate of 14.00% per annum or,
if less, the maximum rate permitted by law. Without relieving Borrower of its
obligation to make timely payments of principal and interest hereunder, if
interest is not paid as provided herein, the amount of interest unpaid shall
bear interest at the same rate as then applicable to the principal sum hereof;
provided, however, that such unpaid interest, so compounded, shall not exceed an
amount equal to simple interest on the unpaid principal at the maximum rate
permitted by law.

        3. DEFAULT BY BORROWER. The entire unpaid balance of the principal
amount of this Promissory Note, together with all interest accrued thereon,
shall become immediately due and payable upon the occurrence of any of the
following:

                  a) Failure of Borrower to make any payment required under this
         Promissory Note within five (5) days following the date when due, or
         breach by Borrower of any other obligation under this Note, if such
         failure or breach continues unabated for five (5) days following notice
         given by Lender in its discretion, provided that upon the third such
         failure or breach the unpaid balance and interest thereon shall become
         due and payable immediately upon notice by Lender, without opportunity
         for cure.

                  b) The appointment of a receiver with respect to any banking
         subsidiary of the Borrower by any federal or state regulator having
         jurisdiction over such subsidiary.

                  c) (i) The filing by Borrower of a voluntary petition in
         bankruptcy, a voluntary petition for the appointment of a receiver or
         for other similar relief under the laws of any 


                                   Page 1 of 2

<PAGE>


         State, or a voluntary assignment by Borrower of all or substantially 
         all of its assets for the benefit of creditors; or (ii) the filing of
         an involuntary petition in bankruptcy against Borrower, if an order
         for relief is entered thereon, if such petition is not dismissed
         within sixty (60) days after its filing, or if Borrower by any action
         or failure to act signifies its approval thereof or consent or
         acquiescence thereto.

        4. ACCELERATION BY LENDER UPON CERTAIN EVENTS. At the election of Lender
and in Lender's sole discretion, the entire unpaid balance of this Promissory
Note, together with all interest accrued thereon, shall become due and payable
at any time on and after such date as Lender ceases to own, of record or
beneficially, at least twenty-five percent (25%) of the outstanding common
equity of Borrower, unless Lender ceases to own such percentage as a consequence
of a Voluntary Lender Action. As used herein, a Voluntary Lender Action means a
transfer by Lender of shares of Borrower's common equity that is not effected in
connection with a merger of Borrower with another entity or a tender offer made
with respect to the common equity of Borrower. Any acceleration of this
Promissory Note by Lender pursuant to this Section 4 shall be effected upon not
less than thirty (30) days notice given by Lender, which notice may be given in
anticipation of the event constituting the basis for such acceleration,
conditioned upon the subsequent occurrence of such event.

        5. COLLECTION COSTS BORNE BY BORROWER. In the event of any default by
Borrower hereunder, including any failure on the part of Borrower to make any
payment when the same is due, Lender shall be entitled to recover from Borrower
all costs of enforcing or collecting this Promissory Note, including reasonable
attorneys' fees and all costs of collection. Any such amounts shall be added to
principal at the time of demand by Lender and shall bear interest until paid at
the default rate of interest.

        6.        GOVERNING LAW.  This Note shall be enforced in
accordance with the laws of the State of Delaware and shall be
construed in accordance therewith.

        7.        SUCCESSORS.  This Agreement shall be binding upon and
shall inure to the benefit of the parties hereto and their
respective successors and assigns.

         IN WITNESS WHEREOF, Commerce Security Bancorp, Inc. has
caused this Promissory Note to be executed and delivered as of
the date set forth above.


                                COMMERCE SECURITY BANCORP, INC.
                                A Delaware Corporation



                                BY:
                                   ----------------------------------------
                                   Curt A. Christianssen, Senior Vice President
                                   and Chief Financial Officer


                                   Page 2 of 2