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                                                                  EXHIBIT 4.1(b)

                          AMENDMENT NO. 1 TO INDENTURE

         AMENDMENT (this "Amendment"), dated as of January 28, 2000, to the
Indenture, dated as of February 1, 1998 (the "Indenture"), among Mentus Media
Corp., a Delaware corporation and now known as Next Generation Network, Inc.
(the "Company"), and United States Trust Company of New York, a banking
corporation organized and existing under the laws of the State of New York, in
its capacity as trustee (the "Trustee").

                                   WITNESSETH:

         WHEREAS, the Company proposes to amend the Indenture in accordance with
Article 9 thereof;

         WHEREAS, the Company has obtained the consents of the requisite number
of Securityholders (as defined in the Indenture) to amend the Indenture;

         NOW THEREFORE, in consideration of the premises and the mutual
agreements contained herein and other good and valuable consideration, the
parties hereto agree as follows:

         SECTION 1. Definitions. All capitalized terms not otherwise defined in
this Amendment are used herein as defined in the Indenture.

         SECTION 2. Amendment to the Indenture. The Indenture is hereby amended
effective as of the date hereof as follows:

         (i) The definition of an "Asset Disposition" is amended by adding the
underscored and bold language below.


                  "Asset Disposition" means any sale, lease, transfer, issuance
         or other disposition (or series of related, sales, leases, transfers,
         issuances or dispositions that are part of a common plan) of shares of
         Capital Stock of (or any other equity interests in) a Restricted
         Subsidiary (other than directors' qualifying shares) or of any other
         property or other assets (each referred to for the purposes of this
         definition as a "disposition") by the Company or any of its Restricted
         Subsidiaries (including any disposition by means of a merge,
         consolidation or similar transaction) other than (i) a disposition by a
         Restricted Subsidiary to the Company or by the Company or a Restricted
         Subsidiary to a Wholly-Owned Subsidiary, (ii) a disposition of
         inventory in the ordinary course of business, (iii) a disposition of
         obsolete or worn out equipment or equipment that is no longer useful in
         the conduct of the business of the Company and its Restricted
         Subsidiaries and that is disposed of in the ordinary course of
         business, (iv) dispositions of property for net proceeds which, when
         taken collectively with the net proceeds of any other such dispositions
         under this clause (iv) that were consummated since the beginning of the
         calendar year in which such disposition is consummated, do not exceed
         $100,000, (V) THE



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         LICENSING OF TECHNOLOGY, KNOW-HOW AND OTHER INTELLECTUAL PROPERTY and
         (vi) transactions permitted under Section 5.01.


         (ii) The definition of a "Continuing Director" is amended by adding the
underscored and bold language below.


                  "Continuing Director" of any Person means, as of the date of
         determination, any Person who (i) was a member of the Board of
         Directors of such Person on the date of the Indenture; (ii) was
         nominated for election or elected to the Board of Directors of such
         Person with the affirmative vote of a majority of the Continuing
         Directors of such Person who were members of such Board of Directors at
         the time of such nomination or election; or (iii) was nominated or
         elected to the Board of Directors in accordance with the provisions of
         the Stockholders Agreement dated as of September 25, 1996, as amended
         by the First Amendment to the Stockholders Agreement dated as of August
         29, 1997, as such agreement may be further amended or supplemented from
         time to time; OR (IV) WAS NOMINATED OR ELECTED TO THE BOARD OF
         DIRECTORS IN ACCORDANCE WITH THE PROVISIONS OF THE AMENDED AND RESTATED
         STOCKHOLDERS AGREEMENT DATED AS OF JANUARY 28, 2000, AS SUCH AGREEMENT
         MAY BE AMENDED OR SUPPLEMENTED FROM TIME TO TIME.


         (iii) Section 4.11(a) of the Indenture is amended by adding the
underscored and bold language below and deleting the crossed out language below:

         SECTION 4.11.  LIMITATION ON AFFILIATE TRANSACTIONS.


                  (a) The Company will not, and will not permit any of its
         Restricted Subsidiaries to, directly or indirectly, enter into or
         conduct any transaction or series of related transactions for(the
         purchase, sale, lease or exchange of any property or the rendering
         of any service) with or for the benefit of any Affiliate of the
         Company, other than a Wholly-Owned Subsidiary (an "Affiliate
         Transaction") unless: (i) the terms of such Affiliate Transaction are
         no less favorable to the Company or such Restricted Subsidiary, as the
         case may be, than those that could be obtained at the time of such
         transaction in arm's length dealings with a Person who is not such an
         Affiliate; (ii) in the event such Affiliate Transaction involves an
         aggregate amount in excess of $100,000, the terms of such transaction
         have been approved by a majority of the members of the Board of
         Directors of the Company and by a majority of the disinterested members
         of such Board, if any (and such majority or majorities, as the case may
         be, determines that such Affiliate Transaction satisfies the criteria
         in (i) above); and (iii) in the event such Affiliate Transaction
         involves an aggregate amount in excess of $10,000,000, the Company has
         received a written opinion from an independent investment banking firm
         of nationally recognized standing that such Affiliate Transaction is
         fair to the Company or such Restricted Subsidiary, as the case may be,
         from a financial point of view; provided, however, that (X) advertising
         contracts entered into in the ordinary course of business between the
         Company and ANY OF ITS AFFILIATES AND (Y) LICENSING AND OTHER
         COMMERCIAL ARRANGEMENTS BETWEEN THE COMPANY AND OTIS ELEVATOR COMPANY
         AND/OR ITS AFFILIATES need only be approved in the manner contemplated
         in (A)(I) AND (a)(ii) above.


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                  (b) The foregoing paragraph (a) shall not apply to (i) any
         issuance of securities, or other payments, awards or grants in cash,
         securities or otherwise pursuant to, or the funding of, employment
         arrangements, or any stock options and stock ownership plans for the
         benefit of employees, officers and directors, consultants and advisors
         approved by the Board of Directors of the Company, (ii) loans or
         advances to employees in the ordinary course of business of the Company
         or any of its Restricted Subsidiaries in aggregate amount outstanding
         not to exceed $100,000 at any time, (iii) any transaction between
         Wholly-Owned Subsidiaries, (iv) indemnification agreements with, and
         the payment of fees and indemnities to, directors, officers and
         employees of the Company and its Restricted Subsidiaries, in each case
         in the ordinary course of business, (v) transactions pursuant to
         agreements in existence on the Issue Date which are (x) described in
         the Offering Memorandum or (y) otherwise, in the aggregate, immaterial
         to the Company and its Restricted Subsidiaries taken as a whole, (vi)
         any employment, non-competition or confidentiality agreements entered
         into by the Company or any of its Restricted Subsidiaries with its
         employees in the ordinary course of business, (vii) THE AMENDED AND
         RESTATED STOCKHOLDERS AGREEMENT DATED AS OF JANUARY 28, 2000 AMONG THE
         COMPANY AND CERTAIN OF ITS SECURITY HOLDERS, THE AMENDED AND RESTATED
         REGISTRATION RIGHTS AGREEMENT DATED AS OF JANUARY 28, 2000 AMONG THE
         COMPANY AND CERTAIN OF ITS SECURITY HOLDERS, THE WARRANT AGREEMENT
         BETWEEN THE COMPANY AND UNITED STATES TRUST COMPANY OF NEW YORK DATED
         AS OF FEBRUARY 18, 1998, AND THE COMMON STOCK REGISTRATION RIGHTS AND
         STOCKHOLDERS AGREEMENT BETWEEN THE COMPANY AND NATWEST CAPITAL MARKETS
         LIMITED, AS INITIAL PURCHASER, IN EACH CASE AS THE SAME MAY BE AMENDED
         FROM TIME TO TIME and (viii) the issuance of Capital Stock of the
         Company (other than Disqualified Stock).


         SECTION 3. APPLICABLE LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

         SECTION 4. Headings. The headings of this Amendment are for the
purposes of reference only and shall not affect the construction of, or
be taken into consideration in interpreting, this Amendment.

         SECTION 5. Counterparts. This Amendment may be executed in
counterparts, each of which shall be deemed an original, but which
taken together shall constitute one agreement.

         SECTION 6. The Trustee. The Trustee is not responsible in any manner
whatsoever for or in respect of the validity or sufficiency of this
Amendment or for or in respect of the recitals contained herein, all of which
are made solely by the Company.

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                  IN WITNESS WHEREOF, the undersigned have caused this Amendment
to be duly executed as of the date and year first written above.

                                             NEXT GENERATION NETWORK, INC.


                                             By:______________________________
                                             Name:____________________________
                                             Title:___________________________



                                             UNITED STATES TRUST COMPANY OF NEW
                                               YORK, as Trustee


                                             By:______________________________
                                             Name:____________________________
                                             Title:___________________________

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