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                                                                     EXHIBIT 4.3

THIS WARRANT AND THE PREFERRED STOCK OR COMMON STOCK RECEIVABLE UPON THE
EXERCISE HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 ("THE
ACT"), OR ANY STATE SECURITIES LAWS. THEY MAY NOT BE TRANSFERRED OR OFFERED FOR
SALE IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR AN
OPINION OF COUNSEL, REASONABLY SATISFACTORY TO THE COMPANY, TO THE EFFECT THAT
REGISTRATION IS NOT REQUIRED.

              VOID AFTER 5:00 P.M., PACIFIC TIME, ON MARCH 28, 2007

            WARRANT TO PURCHASE SERIES A CONVERTIBLE PREFERRED STOCK

                                  CENTIV, INC.

WARRANT NO. ______              ORIGINAL ISSUE DATE:  MARCH 28, 2002

        This is to Certify That, FOR VALUE RECEIVED, _________ ("Holder") is
entitled to purchase, subject to the provisions of this Warrant, from CENTIV,
INC. (the "Company"), at any time until 5:00 P.M., Pacific Time, on March 28,
2007 ("Expiration Date"), 1,000 shares ("Shares") of the Company's Series A
Convertible Preferred Stock, $.001 par value per share ("Preferred Stock"),
which number is subject to adjustment from time to time as provided in this
Warrant. The shares of Preferred Stock are convertible into shares of the
Company's Class A Common Stock, $.001 per share ("Common Stock"), initially at
the rate of ten (10) shares of Common Stock for each one (1) share of Preferred
Stock. The exercise price of the Warrant shall be $15.00 per Share, subject to
adjustment as provided in Section 8 hereof ("Exercise Price").

        This Warrant has been issued pursuant to the Securities Purchase
Agreement dated March 28, 2002, among the Company and the purchasers identified
therein (as amended from time to time, the "Purchase Agreement"). The Holder is
entitled to the rights in the Purchase Agreement and in the Investor Rights
Agreement dated March 28, 2002 among the Company and the aforementioned
purchasers (as amended from time to time, the "Investor Rights Agreement"),
including the rights relating to the registration of the shares of Common Stock
issuable upon conversion of the Preferred Stock issued hereunder or otherwise
issuable under this Warrant (collectively, the "Common Shares"), unless the
Holder is not a party to those agreements and has not been validly assigned
rights therein.

        1. EXERCISE OF WARRANT. This Warrant may be exercised in whole or in
part at any time or from time to time until the Expiration Date or if the
Expiration Date is a day on which banking institutions are authorized by law to
close, then on the next succeeding day which shall not be such a day, by
presentation and surrender hereof to the Company or at the office its stock
transfer agent, if any, with the Purchase Form annexed hereto as Exhibit A duly
executed and accompanied by payment of the Exercise Price for the number of
Shares specified in such Form, in cash or check payable to the order of the
Company. The Shares so purchased shall be deemed to be issued to the Holder or
the Holder's designee, as the record owner of such shares, as of the close of
business on the date on which this Warrant

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shall have been surrendered and the completed Exhibit A shall have been
delivered and payment shall have been made for such Shares as set forth above
or, if such day is not a business day, on the next succeeding business day. The
Shares so purchased, representing the aggregate number of shares specified in
the executed Exhibit A, shall be delivered to the holder hereof within a
reasonable time, not exceeding ten (10) business days, after this Warrant shall
have been so exercised. If (a) the Holder is exercising this Warrant for shares
of Common Stock, (b) the Company's transfer agent is participating in the
Depository Trust Company ("DTC") Fast Automated Securities Transfer program, and
(c) the certificates therefor are not required to bear a legend and the holder
is not obligated to return such certificate for the placement of a legend
thereon, the Company, upon request of the Holder, shall cause its transfer agent
to electronically transmit the Shares so purchased to the Holder by crediting
the account of the holder or its nominee with DTC through its Deposit Withdrawal
Agent Commission system ("DTC Transfer"). If the aforementioned conditions to a
DTC Transfer are not satisfied or such transfer is not so requested by the
Holder, the Company shall deliver to the holder physical certificates
representing the Shares so purchased.

        If this Warrant is exercised in part only, the Company shall, upon
surrender of this Warrant for cancellation, execute and deliver a new Warrant
evidencing the right of the Holder to purchase the balance of the Shares
purchasable hereunder. Upon receipt by the Company of this Warrant at the office
of the Company, in proper form for exercise and accompanied by the Exercise
Price, the Holder shall be deemed to be the holder of record of the Shares
issuable upon such exercise, notwithstanding that the stock transfer books of
the Company shall then be closed or that certificates representing such Shares
shall not then be actually delivered to the Holder.

        2. REDEMPTION. During the term of this Warrant, the Company will have
the right to redeem all of the Warrants on fifteen (15) business days' prior
written notice (the period from the date notice is given to the date of
redemption being referred to as the "Notice Period") at a redemption price of
$0.10 (as appropriately adjusted for stock splits, reverse stock splits and
other events described in Section 8, including the conversion of all outstanding
shares of Preferred Stock to Common Stock so that the aggregate redemption price
remains unchanged) per Share any time after both of the following two conditions
have been satisfied: (i) the "Market Price" per share of Common Stock, as
defined below, has equaled or exceeded $1.80 (as adjusted for stock splits,
reverse stock splits and the like) for a period of ten (10) consecutive Trading
Days (as defined below); and (ii) a registration statement covering the resale
of the Common Shares has been declared effective by the Securities and Exchange
Commission and, during such 10-trading day period and at the time that such
notice was given, the registration statement remained effective and no
Suspension Periods (as defined in the Investor Rights Agreement) were then in
effect; provided, that for such redemption to be effective such registration
statement must also remain effective throughout the Notice Period. If the
Company elects to exercise its redemption right, the Holder of this Warrant may
either exercise the Warrant, in whole or in part, or tender the Warrant to the
Company for redemption, in whole or in part. Within ten (10) business days after
the expiration of the Notice Period, the Company will mail a redemption check
for the redemption price to the Holder of this Warrant should any portion of the
Warrant remain outstanding at the end of the Notice Period, whether or not the
Holder has surrendered this Warrant for redemption. This Warrant shall not be
exercisable after the expiration of the Notice Period, provided that the Company
mails the redemption check in the period provided in the previous sentence.
"Market Price" per share of Common Stock on a particular day means (i) the last
sale price on such day on the principal national stock exchange or quotation
system on which the Common Stock is then listed or admitted to trading, or (ii)
if no sale takes place on such date on any such exchange or quotation system,
the average of the reported closing bid and asked prices on such day as
officially noted on any such exchange or quotation system. "Trading Day" shall
mean a business day on which at least 25,000 shares of Common Stock are traded
on the principal United States securities exchange or automated quotation system
on which such security is listed or traded. The Warrants may not be redeemed at
any time that the Common Stock is not trading on a

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national stock exchange or automated quotation system or trading in Common Stock
has been suspended by the exchange or automated quotation system.

        3. RESERVATION OF SHARES. The Company hereby agrees that at all times
that this Warrant remains outstanding there shall be reserved for issuance
and/or delivery upon exercise of this Warrant such number of Shares and Common
Shares as shall be required for issuance or delivery upon exercise of this
Warrant and/or conversion of the Shares.

        4. LIMIT ON FRACTIONAL SHARES. No fractional Shares, shares or scrip
representing fractional shares shall be issued upon the exercise of this
Warrant.

        5. SHARES TO BE FULLY PAID. All Shares will, upon issuance in accordance
with the terms of this Warrant, be validly issued, fully paid and nonassessable
and free from all taxes, liens, claims and encumbrances.

        6. EXCHANGE, ASSIGNMENT OR LOSS OF WARRANT. This Warrant is
exchangeable, without expense, at the option of the Holder, upon presentation
and surrender hereof to the Company for other Warrants of different
denominations entitling the Holder thereof to purchase (under the same terms and
conditions as provided by this Warrant) in the aggregate the same number of
Shares purchasable hereunder. Subject to Section 12, any transfer or assignment
shall be made by surrender of this Warrant to the Company with the Assignment
Form annexed hereto as Exhibit B duly executed and with funds sufficient to pay
any transfer tax; whereupon the Company shall, without charge, execute and
deliver a new Warrant in the name of the assignee named in such instrument of
assignment and this Warrant shall promptly be canceled. This Warrant may be
divided or combined with other Warrants which carry the same rights upon
presentation hereof at the office of the Company or at the office of its stock
transfer agent, if any, together with a written notice specifying the names and
denominations in which new Warrants are to be issued and signed by the Holder
hereof. The term "Warrant" as used herein includes any warrants issued in
substitution for or replacement of this Warrant, or into which this Warrant may
be divided or exchanged. Upon receipt by the Company of evidence satisfactory to
it of the loss, theft, destruction or mutilation of this Warrant, and (in the
case of loss, theft or destruction) of reasonably satisfactory indemnification,
and upon surrender and cancellation of this Warrant, if mutilated, the Company
will execute and deliver a new Warrant of like tenor and date. Subject to such
right of indemnification, any such new Warrant executed and delivered shall
constitute an additional contractual obligation on the part of the Company,
whether or not this Warrant so lost, stolen, destroyed, or mutilated shall be at
any time enforceable by anyone.

        7. RIGHTS OF THE HOLDER. The Holder shall not, by virtue hereof, be
entitled to any rights of a shareholder in the Company, either at law or equity,
and the rights of the Holder are limited to those expressed in the Warrant (and,
if the Holder is a party or an assignee or rights therein, the Purchase
Agreement and the Investor Rights Agreement) and are not enforceable against the
Company except to the extent set forth herein (or therein).

        8. ADJUSTMENT PROVISIONS. The number and type of shares issuable upon
exercise of this Warrant shall be subject to adjustment from time to time as
follows:

               (a) If the number of shares of Preferred Stock outstanding is
        increased by a stock dividend payable in shares of Preferred Stock or by
        a subdivision or split-up of shares of Preferred Stock, then, following
        the record date for the determination of holders of Preferred Stock
        entitled to receive such stock dividend, subdivision or split-up, the
        number of shares of Preferred Stock for which this Warrant is
        exercisable and the Exercise Price shall be appropriately adjusted so
        that the number of shares of Preferred Stock issuable on exercise of
        this

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        Warrant shall be increased, and the Exercise Price shall be decreased,
        in proportion to such increase in outstanding shares.

               (b) If the number of shares of Preferred Stock outstanding is
        decreased by a combination of the outstanding shares of Preferred Stock,
        then, following the record date for such combination, the number of
        shares of Preferred Stock for which this Warrant is exercisable and the
        Exercise Price shall be appropriately adjusted so that the number of
        shares of Preferred Stock issuable on exercise of this Warrant shall be
        decreased, and the Exercise Price increased, in proportion to such
        decrease in outstanding shares.

               (c) In the event of any capital reorganization of the Company,
        any reclassification of the stock of the Company (other than a change in
        par value or from no par value to par value or from par value to no par
        value or as a result of a stock dividend or subdivision, split-up or
        combination of shares), any consolidation or merger of the Company, or
        any sale, lease, conveyance to another person of the property of the
        Company pursuant to which the Company's Preferred Stock is converted
        into other securities, cash or assets, each Warrant shall after such
        reorganization, reclassification, consolidation, merger or conveyance be
        exercisable into the kind and number of shares of stock or other
        securities or property of the Company or of the corporation resulting
        from such consolidation or surviving such merger to which the holder of
        the number of shares of Preferred Stock deliverable (immediately prior
        to the time of such reorganization, reclassification, consolidation or
        merger) upon exercise of such Warrant would have been entitled upon such
        reorganization, reclassification, consolidation, merger or conveyance.
        The provisions of this clause shall similarly apply to successive
        reorganizations, reclassifications, consolidations, mergers or
        conveyances.

               (d) If any event occurs of the type contemplated by the
        adjustment provisions of this Section 8 but not expressly provided for
        by such provisions, the Company will give notice of such event to the
        Holders, and the Company's Board of Directors will make an appropriate
        adjustment in the Exercise Price and the number of shares of Preferred
        Stock acquirable upon exercise of this Warrant so that the rights of the
        holder shall be neither enhanced nor diminished by such event.

               (e) Notwithstanding anything to the contrary contained in this
        Warrant, in the event that all outstanding shares of the Preferred Stock
        are converted into Common Stock or redeemed, this Warrant shall
        immediately cease to be exercisable for shares of Preferred Stock and
        shall thereafter entitle the Holder to receive upon exercise that number
        of shares of Common Stock into which the Shares otherwise issuable on
        exercise of this Warrant would have been convertible at the time of such
        conversion or redemption, subject to the adjustments of this Section 8.
        Appropriate adjustment shall be made in the Exercise Price per share so
        that the aggregate Exercise Price for purchasing all shares issuable
        under this Warrant shall remain unchanged. By way of example, if all of
        the Preferred Stock converted into Common Stock at a time when the
        conversion ratio had not changed from the initial conversion ratio of
        ten (10) shares of Common Stock for each one (1) share of Preferred
        Stock and no adjustments had been made pursuant to the other paragraphs
        of this Section 8, then the number of shares of Common Stock issuable
        upon exercise of this Warrant would be ten times the number of shares of
        Preferred Stock issuable hereunder and the Exercise Price per share
        would change from $15.00 to $1.50. In addition to the foregoing, at any
        time after such conversion or redemption, the references in Sections 8
        and 10 of this Warrant to "Preferred Stock" shall instead be read as
        references to "Common Stock" and references in this Warrant to "Shares"
        shall be read to mean shares of Common Stock issuable upon exercise
        hereof.

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        9. STATEMENT OF ADJUSTMENT. Whenever the Exercise Price shall be
adjusted as provided in Section 8, the Company shall make available for
inspection by the Holder during regular business hours, at its principal
executive offices or at such other place as may be designated by the Company, a
statement, signed by its chief executive officer or president, showing in detail
the facts requiring such adjustment and the Exercise Price that shall be in
effect after such adjustment. The Company shall also cause a copy of such
statement to be sent by first class certified mail, return receipt requested and
postage prepaid, to Holder at such Holder's address appearing on the Company's
records.

        10. NOTIFICATION OF OTHER EVENTS. In case at any time:

        (a) the Company shall declare any dividend upon the Preferred Stock
payable in shares of stock of any class or make any other distribution (other
than dividends or distributions payable in cash out of retained earnings
consistent with the Company's past practices with respect to declaring dividends
and making distributions) to the holders of the Preferred Stock;

        (b) the Company shall offer for subscription pro rata to the holders of
the Preferred Stock any additional shares of stock of any class or other rights;

        (c) there shall be any capital reorganization of the Company, or
reclassification of the Preferred Stock, or consolidation or merger of the
Company with or into another corporation or entity such that the holders of the
Company's capital stock immediately prior to such transaction or series of
related transactions hold less than 50% of the capital stock of the surviving
corporation or entity immediately after such transaction or series of
transactions, or sale of all or substantially all of the Company's assets to
another corporation or entity; or

        (c)  there shall be a voluntary or involuntary dissolution, liquidation
or winding-up of the Company;

then, in each such case, the Company shall give to the Holder (i) notice of the
date or estimated date on which the books of the Company shall close or a record
shall be taken for determining the holders of Preferred Stock entitled to
receive any such dividend, distribution, or subscription rights or for
determining the holders of Preferred Stock entitled to vote in respect of any
such reorganization, reclassification, consolidation, merger, sale, dissolution,
liquidation or winding-up and (ii) in the case of any such reorganization,
reclassification, consolidation, merger, sale, dissolution, liquidation or
winding-up, notice of the date (or, if not then known, a reasonable estimate
thereof by the Company) when the same shall take place. Such notice shall also
specify the date on which the holders of Preferred Stock shall be entitled to
receive such dividend, distribution, or subscription rights or to exchange their
Preferred Stock for stock or other securities or property deliverable upon such
reorganization, reclassification, consolidation, merger, sale, dissolution,
liquidation, or winding-up, as the case may be. Such notice shall be given at
least twenty (20) days prior to the record date or the date on which the
Company's books are closed in respect thereto. The Company shall publicly
disclose the events with respect to which any notice delivered hereunder relates
prior to delivery of such notice to the holder of this Warrant.

        11. NOTICES. Unless otherwise provided herein, any notice, request,
instruction or other document to be given hereunder by any party shall be in
writing and delivered in person or by courier or by facsimile transmission
(followed by mailing certified mail, postage prepaid, return receipt requested)
or mailed by certified mail, postage prepaid, return receipt requested, as
follows: (a) to the Holder at the Holder's address as it appears in the records
of the Company or at such other address as the Holder may otherwise indicate in
a written notice delivered to the Company or (b) to the Company, at 998 Forest
Edge Drive, Vernon Hills, IL 60061, Attn: President, or at such other address as
the Company may

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otherwise indicate in a written notice delivered to Holder. All such notices,
requests, instructions, documents and other communications will (i) if delivered
personally to the address as provided in this Section 11, be deemed given upon
delivery, (ii), if delivered by facsimile transmission to the facsimile number
as provided in this Section 8, be deemed given upon receipt, and (iii) if
delivered by mail in the manner described above to the address as provided in
this Section 11, five (5) days after being placed in the mail.

        12. TRANSFER TO COMPLY WITH THE SECURITIES ACT OF 1933. The Company may
cause the following legend, or one similar thereto, to be set forth on each
certificate representing the Shares or any other security issued or issuable
upon exercise of this Warrant:

        The securities represented by this certificate may not be offered for
        sale, sold or otherwise transferred in the absence of an effective
        registration statement under the Securities Act of 1933 (the "Act"), and
        under any applicable state securities law, an opinion of counsel
        satisfactory to the Company that such registration is not, in the
        circumstances required, or evidence satisfactory to the Company that the
        Shares have been sold in compliance with Rule 144 promulgated under the
        Act.

        Neither this Warrant nor any Shares or Common Shares issued upon the
exercise hereof shall be transferred other than pursuant to an effective
registration statement under the Securities Act or an exemption from the
registration provisions thereof. Notwithstanding the foregoing, following the
date on which the Shares have been registered under the Securities Act of 1933,
as amended (the "Act"), pursuant to the Investor Rights Agreement or otherwise
may be sold by the holder pursuant to Rule 144(k) promulgated under the Act (or
a successor rule), the Shares shall not bear any restrictive legend.

        13. EXEMPTION FROM REGISTRATION FOR WARRANT EXERCISE.

        The Company and the Holder acknowledge that the Company will be relying
on an exemption from the registration requirements of the Act to deliver Shares
to the Holder(s) upon the exercise of the Warrant. The Holder agrees to provide
the Company with such information and representations as may be requested by the
Company in order to establish a claim to an exemption from the registration
requirements of the Act, and any applicable state securities laws, including, a
representation that the Holder(s) are taking the Shares or Common Shares for
investment, and not with a view to distribution.

        14. GOVERNING LAW; JURISDICTION. This Warrant shall be governed by and
construed in accordance with the laws of the State of California applicable to
contracts made and to be performed in the State of California. Each of the
Company and the Holder irrevocably consents to the non-exclusive jurisdiction of
the United States federal courts and state courts located in San Francisco,
California in any suit or proceeding based on or arising under this Warrant.
Each of the Company and the Holder irrevocably waives any objection to the
laying of venue and the defense of an inconvenient forum to the maintenance of
such suit or proceeding in such courts. Each of the Company and the Holder
further agrees that service of process upon it mailed by certified or registered
mail to the address set forth in Section 11 shall be deemed in every respect
effective service of process upon it in any such suit or proceeding. Nothing
herein shall affect the Holder's right to serve process in any other manner
permitted by law. Each of the Company and the Holder agrees that a final
non-appealable judgment in any such suit or proceeding shall be conclusive and
may be enforced in other jurisdictions by suit on such judgment or in any other
lawful manner.

        15. SUCCESSORS AND ASSIGNS. The rights evidenced hereby shall inure to
the benefit of and be binding upon the successors of the Company and the
successors and assigns of the Holder hereof. The

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provisions of this Warrant are intended to be for the benefit of all Holders
from time to time of this Warrant and shall be enforceable by any such Holder.

        16. AMENDMENT. This Warrant may not be modified or amended or the
provisions hereof waived except by the written consent of the Company and the
Holder.

        17. OTHER ACTIONS. The Company will not avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed by it
hereunder, but will at all times in good faith assist in the carrying out of all
the provisions of this Warrant and in the taking of all such action as may
reasonably be requested by the holder of this Warrant in order to protect the
economic benefit inuring to the holder hereof and the exercise privilege of the
holder of this Warrant against dilution or other impairment, consistent with the
tenor and purpose of this Warrant.

                                                CENTIV, INC.

                                                By:
                                                     ---------------------------
                                                      Name:
                                                      Title:

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                                    EXHIBIT A

                                  PURCHASE FORM

                                                      DATED: ____________, 200__

The undersigned hereby irrevocably elects to exercise the Warrant to the extent
of purchasing __________ shares of [Preferred Stock/Common Stock] of Centiv,
Inc., and hereby makes payment of $_____________ in payment of the actual
Exercise Price thereof.

[_] The undersigned requests that the Company cause its transfer agent to
electronically transmit the Common Stock being acquired hereby to the account of
the undersigned or its nominee (which is _________________) with DTC through its
Deposit Withdrawal Agent Commission System ("DTC Transfer").

                     INSTRUCTIONS FOR REGISTRATION OF SHARES

Name:
       ------------------------------------------------------------------------
                  (Please typewrite or print in block letters)

Address:
         ----------------------------------------------------------------------

Signature:
          ---------------------------------------------------------------------

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                                    EXHIBIT B

                                 ASSIGNMENT FORM

                                                        DATED: ___________, 200_

FOR VALUE RECEIVED,
                    ---------------------------------------------

hereby sells, assigns and transfers unto

Name:
         ------------------------------------------------------------------
                  (Please typewrite or print in block letters)

Address:
          ------------------------------------------------------------------

the right to purchase Shares represented by this Warrant to the extent of
______________ shares of [Preferred Stock/Common Stock] as to which such right
is exercisable and does hereby irrevocably constitute and appoint
__________________, attorney, to transfer the same on the books of the Company
with full power of substitution in the premises.

                                                Signature:
                                                          ----------------------