Exhibit 10.20

HERCULES DEVELOPMENT GROUP, INC.
2121 30th Street
Boulder, Colorado   80301
Phone (303) 443-2121
Fax  (303) 449-3555



                          PROPERTY MANAGEMENT AGREEMENT



In consideration of the covenants herein contained, Peter Garthwaite and
                                                    ----------------
Heidi Garthwaite (hereinafter called "Owner"), and Hercules Development Group,
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Inc., or its assignee (hereinafter called "Agent"), agree as follows:


The Owner hereby represents to the Agent that the Owner holds legal title to the
following described property hereinafter called the "Premises." In the event the
legal  Owner is unable  to sign this  Property  Management  Agreement  the legal
representative  of the  Owner may sign on the  Owner's  behalf  after  producing
proper documentation.


EXCLUSIVE MANAGEMENT: The Owner hereby employs the Agent to rent, lease, operate
and manage the property known as:

PROPERTY ADDRESS  1953 Centennial Drive
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LEGAL DESCRIPTION
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CITY Louisville              STATE   CO                     ZIP  80027
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Upon the terms and conditions herein set forth, for the term of 1 year beginning
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on the 1st day of September, 1999, and ending on the 1st day of September, 2000,
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and  thereafter  for periods which are  automatically  renewed  identical to the
original  period.  Either party has the right to cancel this Agreement by giving
the other party 30 days  written  notice of intention to do so. In the event the
Owner terminates this Agreement the Agent shall be entitled to compensation at a
rate of five (5%) percent of the rents on leases put into effect during the term
of this Agreement, with said compensation to be paid prior to the termination of
this Agreement.

MANAGEMENT ACCEPTANCE: The Agent accepts the employment and agrees to manage the
Premises for the period and upon the terms herein provided and agrees to furnish
services for renting,  leasing,  operating and managing the premises.  To render
monthly statements of receipts not later than the last day of the month in which
the rent is  collected.  Statements  and/or checks shall be sent to the name and
address below:

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<PAGE>

NAME
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ADDRESS
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CITY                                STATE                  ZIP
      -----------------------------      -----------------    ------------------

TELEPHONE  (    )
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THE  OWNER  AGREES:  To give  the  Agent  the  following  authority  that may be
exercised in the name of the Owner and the expense thereof assumed by the Owner.
The  Agent  may  advertise  the  premises  for  rent,  display  signs  for rent,
investigate  references of prospective tenants, sign leases for the terms not in
excess of one (1) year,  renew or cancel existing leases and prepare new leases.
The Agent's may, when in the best judgment of the Agent, terminate tenancies and
sign and serve such notices as are deemed  necessary,  select an attorney of the
Agents  choice to  institute  legal  proceedings  to recover  possession  of the
premises or recover  monies  owed to the Owner.  When  deemed  expedient  by the
Agent,  the  Agent  may  release  suits or  actions,  settle  with  the  Tenant,
compromise,  or  reinstate  tenancies.  ANY  EXPENSE OF  LITIGATION  THAT IS NOT
RECOVERED FROM THE TENANT BECOMES AN OWNER EXPENSE TO BE PAID BY THE OWNER.

In the event that the Agent advances monies on behalf of the Owner's account, or
the  Owner  is  indebted  to the  Agent  for  any  reasons  arising  out of this
Agreement, the Owner agrees to promptly pay upon demand such indebtedness to the
Agent. Any such indebtedness not paid within twenty (20) days after notice shall
be charged  interest at the maximum rate  permitted by law and shall  constitute
lien rights upon the property for services, materials and management fees.

RENTAL  AUTHORIZATION:  The Owner authorizes the Agent to rent the premises at a

monthly rate of $1,100 for not less than six (6) months.  If the desired
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monthly  rental  rate cannot be achieved  the Agent is  authorized  to lower the

monthly  rental rate to $1,000  .
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Pets (yes) (no), if yes describe:  yes .
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UTILITIES:  All gas, electric,  and telephone charges incurred by the Tenant are
Tenant expenses.  Water is paid by the Owner. Nominal charges are made by Public
Service to transfer  service back into the Owner's name after a Tenant  vacates.
This is an Owner expense.

ASSOCIATION  DUES: Any Association dues and/or Special  Assessments are an Owner
expense to be paid and kept current by the Owner.

INSURANCE:  The  Owner  agrees to  insure  the  Premises,  at  Owner's  expense,
according to the  recommended  guidelines of the insurance  industry.  Liability
insurance will be carried  adequate to protect both the Owner and the Agent, and
will name the Agent as co-insured.

STATUTES & COVENANTS:  If the Owner  refuses to comply with any Federal,  State,
County,  Municipal,  or other governmental Statute or Association Covenant,  the
Agent upon giving  written  notice to the Owner,  may terminate  this  agreement
within seven (7) days.

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<PAGE>

TRANSFERS:  It is agreed that  premature  vacating of the Premises by the Tenant
does not constitute a liability to the Tenant in the event of military transfer,
corporate transfer, or military or corporate discharge.

REPAIRS & CLEAN-UP:  The Agent is granted full power and  authority by the Owner
to  contract  for any  repairs or clean-up  (costs not to exceed  Three  Hundred
Dollars ($300.00) per item), which in the judgement of the Agent is necessary to
maintain  the  premises in  rentable  condition.  The costs of such  clean-up or
repair  shall be paid out of the Owner's  funds.  This amount may be exceeded in
the event an  emergency  exists that  requires  immediate  action to protect the
Premises or to maintain services to Tenants as called for in the lease.

EMPLOYEES:  The Agent is authorized to hire,  discharge and supervise  employees
and labor  required  for the  maintenance  of the  Premises.  It is agreed  that
employees  shall be deemed the employees of the Owner and not of the Agent.  The
Agent shall not be held liable for the acts of employees  so long as  reasonable
care has been exercised in their appointment and retention.

SECURITY  DEPOSITS:  The Agent shall have exclusive control of security deposits
and pet deposits  and shall have the right to keep said  deposits in an interest
bearing trust account with accrued interest paid to the Agent to offset costs of
bookkeeping and account operating expenses.  Security deposits shall be returned
to the Tenant upon vacation of the premises, at the discretion of the Agent, and
after the Agent  determines if any monies are to be retained due to  outstanding
Tenant debts or damage to the premises,  normal wear and tear  expected.  Monies
retained from the Tenant will be credited to the Owner's funds.

ADVERTISING  COSTS: In the event it becomes  necessary to pay for advertising to
obtain a Tenant, such costs are paid for from the Owner's funds.

AGENT COMPENSATION: A Tenant procurement fee of fifty (50%) percent of the first
month's rent shall be charged for the  acquisition of each new Tenant.  This fee
is not charged when re-leasing to an existing Tenant. The management fee is five
(5%) percent of the monthly  rent after the first month.  No fee is charged when
the premises are vacant.  The minimum  monthly  management fee is fifty ($50.00)
Dollars per property when the premises are occupied.

LATE  CHARGES  AND  RETURNED  CHECK  CHARGES:  Due to the extra  effort and time
required in collecting  late rent and processing  returned checks the Agent will
retain any monies charged of the Tenant for these purposes.

SAVE  HARMLESS:  The Owner agrees to save the Agent  harmless  from all suits in
connection  with  the  management  of the  herein  described  property  and from
liability from injury suffered by any employee or other person.  The Agent shall
not be personally liable for any acts it may do in good faith and exercising its
best  judgement.  The Owner  agrees to promptly  defend any action,  proceeding,
charge  or  prosecution  instituted  against  the  Agent or the  Agent and Owner
jointly related to this agreement.

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<PAGE>


IT IS HEREBY  AGREED  THAT THE AGENT IS NOT  REQUIRED  TO ADVANCE ANY OF ITS OWN
FUNDS FOR MANAGEMENT OF THE HEREIN MENTIONED PROPERTY.

ADDITIONAL TERMS AND CONDITIONS
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                THIS IS A LEGAL DOCUMENT. IF NOT FULLY UNDERSTOOD
                             CONSULT YOUR ATTORNEY.

This  Agreement  shall be binding upon the  successors and assigns of the Agent,
and upon the heirs,  administrators,  executors,  successors  and assigns of the
Owner.

IN WITNESS WHEREOF the parties hereto have affixed or caused to be affixed their
respective signatures this 2nd day of September, 1999.
                           ---        ---------  ----


/s/ J. Peter Garthwaite                        /s/ J. Peter Garthwaite
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       Owner                                          Agent

/s/ Heidi Y. Garthwaite
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       Owner


Social Security Number or Federal I.D. Number ###-##-####
                                              ------------

Owner's FWD Address:  2121 30th St.
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                      Boulder, Colorado  80301
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Owner's Telephone Number: 303-449-3434
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