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                                                                   EXHIBIT 10.17

[MERRILL LYNCH LOGO]                                      UNCONDITIONAL GUARANTY
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FOR VALUE RECEIVED, and in order to induce MERRILL LYNCH BUSINESS FINANCIAL
SERVICES INC. ("MLBFS") to advance moneys or extend or continue to extend credit
or lease property to or for the benefit of, or modify its credit relationship
with, or enter into any other financial accommodations with CREST PROPERTIES,
LTD., a limited partnership organized and existing under the laws of the State
of Texas (with any successor in interest, including, without limitation, any
successor by merger or by operation of law, herein collectively referred to as
"Customer") under: (a) that certain TERM LOAN AND SECURITY AGREEMENT NO.
9904770301 between MLBFS and Customer (the "Loan Agreement"), (b) any
"Additional Agreements", as that term is defined in the Loan Agreement,
including, without limitation, the NOTE incorporated by reference in the Loan
Agreement, and (c) all present and future amendments, restatements, supplements
and other evidences of any extensions, increases, renewals, modifications and
other changes of or to the Loan Agreement or any Additional Agreements
(collectively, the "Guaranteed Documents"), and for other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, THE
UNDERSIGNED, ____________, a corporation organized and existing under the laws
of the State of _________ ("Guarantor"), HEREBY UNCONDITIONALLY GUARANTEES TO
MLBFS: (i) the prompt and full payment when due, by acceleration or otherwise,
of all sums now or any time hereafter due from Customer to MLBFS under the
Guaranteed Documents, (ii) the prompt, full and faithful performance and
discharge by Customer of each and every other covenant and warranty of Customer
set forth in the Guaranteed Documents, and (iii) the prompt and full payment and
performance of all other indebtedness, liabilities and obligations of Customer
to MLBFS, however created or evidenced, and as specified under the Loan
Agreement (collectively, the "Obligations"). Guarantor further agrees to pay all
reasonable costs and expenses (including, but not limited to, court costs and
reasonable attorneys' fees) paid or incurred by MLBFS in endeavoring to collect
or enforce performance of any of the Obligations, or in enforcing this Guaranty.
Guarantor acknowledges that MLBFS is relying on the execution and delivery of
this Guaranty in advancing moneys to or extending or continuing to extend credit
to or for the benefit of Customer.

This Guaranty is absolute, unconditional and continuing and shall remain in
effect until all of the Obligations shall have been fully and indefeasibly paid,
performed and discharged. Upon the occurrence and during the continuance of any
default or Event of Default under the Guaranteed Documents, any or all of the
indebtedness hereby guaranteed then existing shall, at the option of MLBFS,
become immediately due and payable from Guarantor (it being understood, however,
that upon the occurrence of any "Bankruptcy Event", as defined in the Guaranteed
Documents, all such indebtedness shall automatically become due and payable
without action on the part of MLBFS). Notwithstanding the occurrence of any such
event, this Guaranty shall continue and remain in full force and effect. To the
extent MLBFS receives payment with respect to the Obligations, and all or any
part of such payment is subsequently invalidated, declared to be fraudulent or
preferential, set aside, required to be repaid by MLBFS or is repaid by MLBFS
pursuant to a settlement agreement, to a trustee, receiver or any other person
or entity, whether under any Bankruptcy law or otherwise (a "Returned Payment"),
this Guaranty shall continue to be effective or shall be reinstated, as the case
may be, to the extent of such payment or repayment by MLBFS, and the
indebtedness or part thereof intended to be satisfied by such Returned Payment
shall be revived and continued in full force and effect as if said Returned
Payment had not been made.

The liability of Guarantor hereunder shall in no event be affected or impaired
by any of the following, any of which may be done or omitted by MLBFS from time
to time, without notice to or the consent of Guarantor: (a) any renewals,
amendments, restatements, modifications or supplements of or to any of the
Guaranteed Documents, or any extensions, forbearances, compromises or releases
of any of the Obligations or any of MLBFS' rights under any of the Guaranteed
Documents; (b) any acceptance by MLBFS of any collateral or security for, or
other guarantees of, any of the Obligations; (c) any failure, neglect or
omission on the part of MLBFS to realize upon or protect any of the Obligations,
or any collateral or security therefor, or to exercise any lien upon or right of
appropriation of any moneys, credits or property of Customer or any other
guarantor, possessed by or under the control of MLBFS or any of its affiliates,
toward the liquidation or reduction of the Obligations; (d) any invalidity,
irregularity or unenforceability of all or any part of the Obligations, of any
collateral security for the Obligations, or the Guaranteed Documents; (e) any
application of payments or credits by MLBFS; (f) the granting of credit from
time to time by MLBFS to Customer in excess of the amount set forth in the
Guaranteed Documents; or (g) any other act of commission or omission of any kind
or at any time upon the part of MLBFS or any of its affiliates or any of their
respective employees or agents with respect to any matter whatsoever. MLBFS
shall not be required at any time, as a condition of Guarantor's obligations
hereunder, to resort to payment from Customer or other persons or entities
whatsoever, or any of their properties or estates, or resort to any collateral
or pursue or exhaust any other rights or remedies whatsoever.

No release or discharge in whole or in part of any other guarantor of the
Obligations shall release or discharge Guarantor unless and until all of the
Obligations shall have been indefeasibly fully paid and discharged. Guarantor
expressly waives presentment, protest, demand, notice of dishonor or default,
notice of acceptance of this Guaranty, notice of advancement of funds under the
Guaranteed Documents and all other notices and formalities to which Customer or
Guarantor might be entitled, by statute or otherwise, and, so long as there are
any Obligations or MLBFS is committed to extend credit to Customer, waives any
right to revoke or terminate this Guaranty without the express written consent
of MLBFS.

So long as there are any Obligations, Guarantor shall not have any claim, remedy
or right of subrogation, reimbursement, exoneration, contribution,
indemnification, or participation in any claim, right, or remedy of MLBFS
against Customer or any security which MLBFS now has or hereafter acquires,
whether or not such claim, right or remedy arises in equity, under contract, by
statute, under common law, or otherwise.

MLBFS is hereby irrevocably authorized by Guarantor at any time during the
continuance of an Event of Default under the Loan Agreement or any other of the
Guaranteed Documents or in respect of any of the Obligations, in its sole
discretion and without demand or notice of any kind, to appropriate, hold, set
off and apply toward the payment of any amount due hereunder, in such order of
application as MLBFS may elect, all cash, credits, deposits, accounts,
investment property, securities and any other property of Guarantor which is in
transit to or in the possession, custody or control of MLBFS or Merrill Lynch,
Pierce, Fenner & Smith Incorporated ("MLPF&S"), or any of their respective
agents, bailees or affiliates. Guarantor hereby collaterally assigns and grants
to MLBFS a continuing security interest in all such property as additional
security for the Obligations. Upon the occurrence and during the continuance of
an Event of Default, MLBFS shall have all rights in such property available to
collateral assignees and secured parties under all applicable laws, including,
without limitation, the UCC.

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Guarantor agrees to furnish to MLBFS such financial information concerning
Guarantor as may be required by any of the Guaranteed Documents or as MLBFS may
otherwise from time to time reasonably request. Guarantor further hereby
irrevocably authorizes MLBFS and each of its affiliates, including without
limitation MLPF&S, to at any time (whether or not an Event of Default shall have
occurred) obtain from and disclose to each other any and all financial and other
information about Guarantor.

No delay on the part of MLBFS in the exercise of any right or remedy under the
Guaranteed Documents, this Guaranty or any other agreement shall operate as a
waiver thereof, and, without limiting the foregoing, no delay in the enforcement
of any security interest, and no single or partial exercise by MLBFS of any
right or remedy shall preclude any other or further exercise thereof or the
exercise of any other right or remedy. This Guaranty may be executed in any
number of counterparts, each of which counterparts, once they are executed and
delivered, shall be deemed to be an original and all of which counterparts,
taken together, shall constitute but one and the same Guaranty. This Guaranty
shall be binding upon Guarantor and its successors and assigns, and shall inure
to the benefit of MLBFS and its successors and assigns. If there are more than
one guarantor of the Obligations, all of the obligations and agreements of
Guarantor are joint and several with such other guarantors.

This Guaranty shall be governed by the laws of the State of Illinois. WITHOUT
LIMITING THE RIGHT OF MLBFS TO ENFORCE THIS GUARANTY IN ANY JURISDICTION AND
VENUE PERMITTED BY APPLICABLE LAW, GUARANTOR AGREES THAT THIS GUARANTY MAY AT
THE OPTION OF MLBFS BE ENFORCED BY MLBFS IN ANY JURISDICTION AND VENUE IN WHICH
ANY OF THE GUARANTEED DOCUMENTS MAY BE ENFORCED. GUARANTOR AND MLBFS HEREBY EACH
EXPRESSLY WAIVE ANY AND ALL RIGHTS TO A TRIAL BY JURY IN ANY ACTION, PROCEEDING
OR COUNTERCLAIM BROUGHT BY EITHER OF THE PARTIES AGAINST THE OTHER PARTY IN ANY
WAY RELATED TO OR ARISING OUT OF THIS GUARANTY OR THE OBLIGATIONS. Wherever
possible each provision of this Guaranty shall be interpreted in such manner as
to be effective and valid under applicable law, but if any provision of this
Guaranty shall be prohibited by or invalid under such law, such provision shall
be ineffective only to the extent of such prohibition or invalidity, without
invalidating the remainder of such provision or the remaining provisions of this
Guaranty. No modification or waiver of any of the provisions of this Guaranty
shall be effective unless in writing and signed by both Guarantor and an officer
of MLBFS. Each signatory on behalf of Guarantor warrants that he or she has
authority to sign on behalf of Guarantor, and by so signing, to bind Guarantor
hereunder.

Dated as of April 16, 1999.

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By:
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          Signature(2)                       Signature(2)

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          Printed Name                       Printed Name

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          Title                              Title


Address of Guarantor:

         X
         X


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[MERRILL LYNCH LOGO]                                     SECRETARY'S CERTIFICATE

                           (Guaranty by Corporation)


THE UNDERSIGNED HEREBY CERTIFIES TO MERRILL LYNCH BUSINESS FINANCIAL SERVICES,
INC. that the undersigned is the duly appointed and acting Secretary (or
Assistant Secretary) of ___________________, a corporation duly organized,
validly existing and in good standing under the laws of the State of _____; and
that the following is a true, accurate and compared transcript of resolutions
duly, validly and lawfully adopted on the 14 day of April, 1999 by the Board of
Directors of said Corporation acting in accordance with the laws of the state of
incorporation and the charter and by-laws of said Corporation:

"RESOLVED, that it is advisable and in the best interests and to the benefit of
this Corporation to guaranty the obligations of CREST PROPERTIES, LTD.
("Customer") to MERRILL LYNCH BUSINESS FINANCIAL SERVICES INC. ("MLBFS"); and

"FURTHER RESOLVED, that the President, any Vice President, Treasurer, Secretary
or other officer of this Corporation, or any one or more of them, be and each of
them hereby is authorized and empowered for and on behalf of this Corporation
to: (a) execute and deliver to MLBFS: (i) an Unconditional Guaranty of the
obligations of Customer, (ii) any other agreements, instruments and documents
required by MLBFS in connection therewith, including, without limitation, any
agreements, instruments and documents evidencing liens or security interests on
any of the property of this Corporation as collateral for said Unconditional
Guaranty and/or the obligations of Customer to MLBFS, and (iii) any present or
future amendments to any of the foregoing; all in such form as such officer
shall approve, as evidenced by his signature thereon; and (b) to do and perform
all such acts and things deemed by any such officer to be necessary or advisable
to carry out and perform the undertakings and agreements of this Corporation set
forth therein; and all prior acts of each of said officers in these premises are
hereby ratified and confirmed; and

"FURTHER RESOLVED, that MLBFS is authorized to rely upon the foregoing
resolutions until it receives written notice of any change or revocation from an
authorized officer of this Corporation, which change or revocation shall not in
any event affect the obligations of this Corporation with respect to any
transaction conditionally agreed or committed to by MLBFS or having its
inception prior to the receipt of such notice by MLBFS."


THE UNDERSIGNED FURTHER CERTIFIES that: (a) the foregoing resolutions have not
been rescinded, modified or repealed in any manner, are not in conflict with any
agreement of said Corporation and are in full force and effect as of the date of
this Certificate, and (b) the following individuals are now the duly elected and
acting officers of said Corporation and THE SIGNATURES SET FORTH BELOW ARE THE
TRUE SIGNATURES OF SAID OFFICERS.


     President:
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     Vice President:
                    ---------------------------------------------
     Treasurer:
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     Secretary:
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                            :
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     Additional title


IN WITNESS WHEREOF, the undersigned has executed this Certificate and has
affixed the seal of said corporation hereto, pursuant to due authorization, all
as of this 22 day of April, 1999.

(Corporate Seal)
                                        ----------------------------
                                           Secretary

                         Printed Name:
                                        ----------------------------



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