Exhibit 10.19


                 FIFTH AMENDMENT TO SECOND AMENDED AND RESTATED
                     SECURED ADVANCE FACILITY LOAN AGREEMENT


         This FIFTH  AMENDMENT TO SECOND  AMENDED AND RESTATED  SECURED  ADVANCE
FACILITY LOAN AGREEMENT (the  "Amendment") is entered into effective as of March
31, 2001 by and between  Azul  Holdings  Inc., a Delaware  corporation  with its
principal  place of business at 2362 Spotswood  Place,  Boulder,  Colorado 80304
(the  "Borrower"),  and  Jeffrey L.  Neuman as trustee of the Tudor  Trust u/d/t
December 12,  1997,  with an address of 11766  Wilshire  Blvd.,  9th Floor,  Los
Angeles, CA 90025 (the "Lender").

         WHEREAS, the Borrower and the Lender are parties to that Second Amended
and Restated  Secured Advance  Facility Loan Agreement dated as of July 1, 1998,
as  amended by that First  Amendment  to Second  Amended  and  Restated  Secured
Advance  Facility  Loan  Agreement  dated as of December 31,  1998,  that Second
Amendment to Second Amended and Restated Secured Advance Facility Loan Agreement
dated as of  December  7,  1999,  that Third  Amendment  to Second  Amended  and
Restated  Secured Advance Facility Loan Agreement dated as of March 31, 2000 and
that Fourth  Amendment to Second Amended and Restated  Secured Advance  Facility
Loan Agreement dated as of June 19, 2000 (as amended, the "Agreement");

         WHEREAS,  as a result of the  foregoing  the  Borrower  and the  Lender
desire  to  amend  and  modify  the  Agreement  as set  forth  herein,  with all
capitalized  terms used but not defined  herein  having the meanings  given them
under the Agreement;

         NOW, THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency of which are hereby acknowledged, and with the specific intent to be
bound hereby, the parties hereby agree as follows:

         1. Amendments to Agreement. Section 3.1 of the Agreement is amended and
restated in its entirety as follows:

         "3.1 Scheduled  Principal Payment.  Except as set forth in Sections 5.2
         and 8, all Liabilities  shall be paid in full on March 31, 2002, unless
         declared due and payable earlier by the Lender as set forth herein."

         Section 3.2 of the Agreement is amended by the addition  thereto of the
following sentence:
<PAGE>

         "In the event that the Lender fails to elect to receive interest in the
         form of the capital stock of the Borrower as set forth herein, such
         interest shall be added to and become a part of the principal of the
         Liabilities."

         2.  Effect on  Agreement.  Except as  amended  by this  Amendment,  the
Agreement  shall  remain  in full  force  and  effect.  After  the  date of this
Amendment,  every reference in the Agreement to "this  Agreement" shall mean the
Agreement as amended by this Amendment.

         3.       Miscellaneous.

               (a)  Successors  and  Assigns.  The  obligations  of the Borrower
hereunder  shall be binding upon its  successors and assigns (but such reference
is not intended as a consent to any assignment not specifically permitted by the
Lender)  and shall  inure to the  benefit of the  successors  and assigns of the
Lender.

               (b) Counterparts and Facsimile Signatures.  This Amendment may be
executed in two or more counterparts,  each of which shall be deemed an original
but all of which together shall  constitute  one and the same  instrument.  This
Amendment may be executed by facsimile signature.

               (c) Headings.  The section  headings  contained in this Amendment
are inserted for convenience only and shall not affect in any way the meaning or
interpretation of this Amendment.

               (d)  Governing  Law.  This  Amendment  shall be  governed  by and
construed in accordance with the laws of the Commonwealth of  Massachusetts  and
shall constitute an agreement under seal.

               (e) Expenses. The Borrower will pay the reasonable legal fees and
out-of-pocket  expenses of the Lender's  counsel incurred in connection with the
preparation, execution and delivery of this Amendment.

         IN WITNESS WHEREOF, the parties have executed this Amendment as of the
effective date first written above.


BORROWER:                                       LENDER:

AZUL HOLDINGS INC.,
a Delaware corporation

By:      /S/ EDWARD S. WITTMAN                  /S/ JEFFREY L. NEUMAN
         ---------------------                  ---------------------
         Edward S. Wittman                      Jeffrey L. Neuman, as trustee
         Chief Financial Officer                of the Tudor Trust
                                                u/d/t December 12, 1997 and not
                                                individually



<PAGE>


                                    Exhibit A

                  AMENDED AND RESTATED SECURED PROMISSORY NOTE


$17,500,000
Boulder, Colorado                                                 March 31, 2001


         FOR VALUE  RECEIVED,  the  undersigned  AZUL HOLDINGS  INC., a Delaware
corporation  with a principal place of business located at 2362 Spotswood Place,
Boulder, Colorado 80304 (hereinafter,  the "Borrower"),  promises to pay in U.S.
Dollars to the order of Jeffrey L.  Neuman as trustee of the Tudor  Trust  u/d/t
dated December 12, 1997 (hereinafter, with any subsequent holder, the "Lender"),
at the Lender's principal office located at 11766 Wilshire Blvd., 9th Floor, Los
Angeles,  CA 90025, the Liabilities then outstanding  under the loan made by the
Lender to the  Borrower  pursuant to that  certain  Second  Amended and Restated
Secured Advance  Facility Loan Agreement  executed  between the Borrower and the
Lender dated July 1, 1998, as amended by that First  Amendment to Second Amended
and Restated  Secured  Advance  Facility Loan Agreement dated as of December 31,
1998,  that Second  Amendment  to Second  Amended and Restated  Secured  Advance
Facility Loan Agreement  dated as of December 7, 1999,  that Third  Amendment to
Second Amended and Restated  Secured Advance Facility Loan Agreement dated as of
March 31, 2000,  that Fourth  Amendment to Second  Amended and Restated  Secured
Advance  Facility Loan Agreement dated as June 19, 2000 and that Fifth Amendment
to Second Amended and Restated  Secured Advance Facility Loan Agreement dated as
of the date hereof (as amended, the "Loan Agreement"). Advances made pursuant to
the Loan Agreement shall, from time to time after the date hereof, bear interest
at the rate from time to time as provided in the Loan  Agreement,  and after any
Default  under the Loan  Agreement at the rate of twelve (12) percent per annum,
calculated based upon a 360-day year end and actual day months.

         Interest at the rate  provided in the Loan  Agreement  shall be paid as
provided in Section 3.2 of the Loan  Agreement.  Unless a Default under the Loan
Agreement shall have occurred earlier,  the principal balance of this Promissory
Note shall be due and payable in full on March 31, 2001.

         All  payments by the  Borrower to the Lender  under  Article III of the
Loan Agreement shall be applied first to principal and then to interest.

         To secure the obligations of the Borrower under this  Promissory  Note,
(i) the Lender has been  granted a security  interest  in all of the  Borrower's
presently  existing and  hereafter  acquired  property  pursuant to that certain
Sixth Amended and Restated Security  Agreement executed between the Borrower and
Lender dated November 10, 1997 (the "Security  Agreement"),  and (ii) the Lender
has been  granted a security  interest in  2,800,000  shares of Common  Stock of
Xyvision Enterprise  Solutions,  Inc. held of record by the Borrower pursuant to
that certain Pledge Agreement executed between the Borrower and the Lender dated
as of December 31, 1998. All  capitalized  terms used herein,  unless  otherwise
defined  herein,  shall  have  the  meanings  ascribed  to them in the  Security
Agreement.
<PAGE>

         No delay or omission by the Lender in  exercising  or enforcing  any of
the Lender's powers,  rights,  privileges,  remedies or discretions hereunder or
under the Loan  Agreement  shall operate as a waiver thereof on that occasion or
on any other occasion.

         After  demand by the  Lender,  the  Borrower  shall pay all  reasonable
attorney fees and  out-of-pocket  expenses  incurred by the Lender in recovering
the amounts due to the Lender from the Borrower hereunder.

         This  Promissory  Note shall be binding  upon the Borrower and upon its
successors,  assigns and representatives,  and shall inure to the benefit of the
Lender and its successors, endorsees and assigns.

         This  Promissory  Note amends and  restates  that  Amended and Restated
Secured  Promissory Note dated May, 2000 in the principal  amount of $12,357,150
previously  made by the  Borrower  in  favor  of the  Lender,  and is  taken  in
substitution but not in satisfaction thereof.

         This Promissory Note shall be governed by the laws of the  Commonwealth
of Massachusetts and shall take effect as a sealed instrument.


Witnessed:                                           AZUL HOLDINGS INC.,
                                                     a Delaware corporation


                                                     By:
--------------------------------------------            ------------------
                                                        Edward S. Wittman
                                                        Chief Financial Officer