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Exhibit 10.105b

                                 PROMISSORY NOTE

$25,000                                                         APRIL 10, 2003

For  valuable  consideration,  the receipt and  sufficiency  of which are hereby
acknowledged,  the undersigned  Vertical Computer Systems,  Inc.  ("Promissor"),
promises to pay to the order of Vasu Vijay ("Promissee"), in lawful money of the
United States of America the  principal  amount of  Twenty-Five  Thousand and No
Cents ($25,000.00 U.S.),  together with interest on the amount of such principal
outstanding from time to time at the rate of ten (10%) per annum,  calculated on
the basis of a three hundred sixty (360) day year containing  twelve (12) months
of thirty (30) days each (the "Basic  Interest  Rate"),  at the times and in the
manner provided herein.

1. PAYMENT OF PRINCIPAL  AND INTEREST.  Principal and interest  shall be paid as
follows:

         a.  Principal  and  interest  shall be payable  in monthly  installment
payments of $1,000 per month  beginning  on the 10th of each month  beginning in
May 2003,  which will be replaced by $2,000  monthly  installment  payments  per
month beginning in October 2003, with a final monthly payment of under $2,000 to
pay in full any remaining principal, as well as all interest, fees, charges, and
other amounts owing  hereunder.  Promissor shall have a grace period of five (5)
business  days  from the  first of the  month  to make any  payment  as the same
becomes due.

         b. Promissor shall pay all amounts owing under this Note in immediately
available funds to Promissee at Promissee's  address as set forth herein,  or at
such other place as may be specified in writing by Promissee. Each payment, when
made,  shall be credited  first to interest  then due, and then at the option of
Promissee to principal,  late charges,  and other fees and expenses  outstanding
hereunder in such order as Promissee may determine. Payments received after 6:00
p.m. (PST) on any banking day or at any time on any Saturday, Sunday, or holiday
shall be deemed received on the next banking day.

2.  INTEREST RATE UPON DEFAULT.  Should  Promissor  fail to pay any amount owing
hereunder as and when due,  whether the same is due regularly as scheduled or by
reason of  acceleration  following  default or otherwise,  then  interest  shall
accrue on the past due amount at the Basic Interest Rate. Such interest shall be
due and  payable  upon the  earlier  of demand or the first day of the  calendar
month following the month in which the same shall have accrued.

4. DEFAULT;  REMEDIES.  Each of the following  occurrences and conditions  shall
constitute an Event of Default:

         a.  failure  of  Promissor  to pay as and when due  (after the five [5]
business  day  grace  period),  any  money,  whether  principal,   interest,  or
otherwise, under this Note; or

         b.  failure  of  Promissor  to  perform  any  obligation  other than an
obligation to pay money, as and when performance of such obligation is due under
this Note which  failure  continues  for fifteen (15) days after notice  thereof
from Promissee to Promissor; or

         c.  Promissor's  making or at any time having made any  representation,
warranty  or  disclosure  to  Promissee  that  is or  was  materially  false  or
misleading on the date as of which made,  whether or not that  representation or
disclosure appears in any written document concerning the Note.

At any time following the  occurrence of any Event of Default,  or following the
occurrence  of any event as a  consequence  of which the  obligations  evidenced
hereby may be accelerated, then at the election of Promissee and notwithstanding
anything to the contrary  herein or  elsewhere,  the entire  amount of principal
then  outstanding  under this Note and all interest,  fees,  charges,  and other
amounts  owing  and then  unpaid  hereunder  shall  become  immediately  due and
payable,  and  Promissee  may exercise any and all rights that it may have under
any written document concerning the Note, at law, in equity, and otherwise.

                                 Promissory Note

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5. ATTORNEYS'  FEES.  Promissor shall pay to Promissee upon demand all costs and
expenses incurred by Promissee in connection with determination,  protection, or
enforcement of any and all of Promissee's  rights  hereunder or under any of any
written  document  concerning  the Note,  including  enforcement  of any and all
obligations of Promissor  hereunder and thereunder and protection,  enhancement,
or  maintenance  of the security  interests  securing  such  obligations  or the
priority of the same.  Such costs and expenses  shall be payable  whether or not
any suit is instituted, and the same shall include without limitation attorneys'
fees,  expert  witness  fees,  costs  of  investigation,  and all of such  costs
incurred in  connection  with any trial,  appellate  proceeding,  or any case or
proceeding  under Chapters 7, 11, or 13 of the Bankruptcy  Code or any successor
thereto.

6. WAIVER OF NOTICE.  Promissor and each endorser,  guarantor and surety of this
Note  hereby  waive  diligence,  demand,  presentment  for  payment,  notice  of
discharge, notice of nonpayment, protest and notice of protest, and specifically
consent to and waive notice of any renewals or extensions of this Note,  whether
made to or in favor of Promissor or any other person or persons.  Promissor  and
each endorser,  guarantor and surety of this Note further waive and renounce all
rights  to the  benefits  of all  statutes  of  limitation  and any  moratorium,
appraisement,  by any federal exception and homestead now or hereafter  provided
or state law or statute,  including but not limited to exemptions provided by or
allowed under the Bankruptcy Code, both as to each of themselves  personally and
as to all of their property,  whether real or personal,  against the enforcement
and  collection  of the  obligations  evidenced  by  this  Note  and any and all
extensions, renewals and modifications thereof.

7. NOTICES.  All notices  required  hereunder or  pertaining  hereto shall be in
writing  and shall be deemed  delivered  and  effective  upon the earlier of (i)
actual  receipt,  or (ii) the date of  delivery or refusal of the  addressee  to
accept  delivery  if such  notice is sent by express  courier  service or United
States mail, postage prepaid, certified or registered, return receipt requested,
in either case to the applicable address as follows:

To Promissee:     Vasu Vijay
                  3109 Wyndmere Drive
                  Richardson, TX 75082

To Promissor:     Vertical Computer Systems, Inc.
                  6336 Wilshire Boulevard
                  Los Angeles, CA 90048
                  Attn: President

Notwithstanding  the  foregoing,  any notice under or  pertaining to any written
document  concerning  the  Note in  accordance  with  applicable  law  shall  be
effective for purposes  hereof.  Either party may change the address at which it
is to receive notices  hereunder to another  business  address within the United
States (but not a post office box or similar mail  receptacle)  by giving notice
of such change of address in accordance herewith.

9. EXERCISE OF RIGHTS. No single or partial exercise of any of Lenders rights or
powers under this Note or any of the any written  document  concerning  the Note
shall  preclude  any other or further  exercise  thereof or the  exercise of any
other  right or power.  Promissee  at all times  shall have the right to proceed
against any portion of the security  which secures  payment of the  indebtedness
evidenced hereby in such order and manner as Promissee may elect without waiving
any rights  with  respect to any other  portion of such  security.  Each and all
rights and  remedies  of  Promissee  hereunder  and under any  written  document
concerning  the Note are  cumulative  and in addition to each and all other such
rights and remedies.  No exercise of any right or remedy shall preclude exercise
of any other right or remedy.

                                 Promissory Note

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10. NO WAIVER. No failure of Promissee to insist upon strict  performance of any
obligation  of Promissor  or to exercise any right or remedy  hereunder or under
any written document  concerning the Note,  whether before or after any default,
shall constitute or give rise to a waiver thereof,  and no waiver of any default
shall  constitute  a waiver of any future  default or of any other  default.  No
failure to accelerate the debt evidenced  hereby by reason of default  hereunder
or otherwise,  and no acceptance of any past due payment hereunder or acceptance
of any amount less than the amount then due, and no other indulgence that may be
granted by  Promissee  from time to time shall (a)  preclude the exercise of any
right that  Promissee  may have at law, in equity,  by contract or  agreement or
otherwise,  or (b)  constitute  or give  rise to (i) a waiver  of such  right of
acceleration  or any  other  right,  or  (ii)  a  novation  of  this  Note  or a
reinstatement of the debt evidenced  hereby,  or (iii) any waiver of Promissee's
rights  to demand  and  receive  from  Promissor  full and  prompt  payment  and
performance  thereafter,  to impose late charges retroactively,  or to declare a
default. Promissor and each endorser,  guarantor, and surety of this Note hereby
expressly  waive the benefit of any statute or rule of law or equity which would
produce  any  result  contrary  to or  otherwise  in  conflict  with  any of the
foregoing.

11.  ASSIGNMENT;  SUCCESSORS  AND  ASSIGNS.  Promissee  may assign or  otherwise
transfer  all or any part of its interest  herein.  Promptly  following  written
notice  of such  assignment  or other  transfer,  duly  executed  by  Promissee,
Promissor shall render full and complete  performance  hereunder as and when due
to the  transferee so designated  by  Promissee.  Promissor  shall not assign or
transfer all or any of its interests or obligations hereunder, and any attempted
or purported  assignment or transfer by Promissor  shall be void and of no force
or effect,  except to the extent that the same may be expressly  permitted under
the Stock Pledge  Agreements.  Subject to the foregoing,  the terms of this Note
shall apply to, be binding upon,  and inure to the benefit of ail parties hereto
and their successors and assigns.

12.  MODIFICATION.  This Note shall not be  modified,  amended,  or  terminated,
except by written  agreement  duly executed and delivered by both  Promissee and
Promissor.

13.  CONFLICTS.  In the event of any conflict between any provision of this Note
and  any  provision  of the  Stock  Pledge  Agreements,  which  conflict  cannot
reasonably be resolved in such a way as to give effect to all provisions  herein
and therein contained, this Note shall govern.

14. SEVERABILITY.  If any provision of this Note or any payments pursuant to the
terms hereof shall be invalid or unenforceable  to any extent,  the remainder of
this Note and any other  payments  hereunder  shall not be affected  thereby and
shall be enforceable to the greatest extent permitted by law.

15.  GOVERNING  Law.  This Note shall be governed by and construed in accordance
with the laws of the State of California.

         IN WITNESS  WHEREOF,  Promissor has executed and delivered this Note as
of the date first written above.

                                        VERTICAL COMPUTER SYSTEMS, INC.

                                        By __________________________
                                                 Richard Wade, President

                                 Promissory Note

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Exhibit 10.105c

April 14, 2003

This letter will confirm our mutual  understanding of January 15, 2003 regarding
our  agreement  whereby  you  will  assist  Vertical   Computer  Systems,   Inc.
("Vertical").  You  and  Vertical  confirm  and  agree  that,  subject  to  your
professional  commitments,  you will assist and provide  Vertical with strategy,
sales, marketing, and administration services upon Vertical's reasonable request
for a period of 12 months.

Vertical  agrees to extend your warrants and stock options issued to you in 2001
for one (1) year and shall also issue 1,100,000  shares of Vertical common stock
to you within 90 days. If the  foregoing is  acceptable  to you,  please sign as
provided below.

Very truly yours,

Richard Wade
President/CEO
Vertical Computer Systems, Inc.

ACCEPTED AND AGREED:

Vasu Vijay, an individual

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