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                                                                   EXHIBIT 10.16

                       THIRD AMENDMENT TO CREDIT AGREEMENT
                       -----------------------------------

         This THIRD AMENDMENT TO CREDIT AGREEMENT (this "Amendment"), dated as
of August 31, 1998, is by and among RINGER CORPORATION ("Ringer"), SAFER, INC.
("Safer") and SURECO, INC. ("SureCo") (Ringer, Safer and SureCo are sometimes
referred to herein individually as a "Borrower and collectively as the
"Borrowers") and GENERAL ELECTRIC CAPITAL CORPORATION, a New York corporation,
as Lender.

                                    RECITALS
                                    --------

         A. Borrowers and Lender are parties to that certain Credit Agreement
dated as of May 2, 1997 (as from time to time amended, restated, supplemented or
otherwise modified and in effect, the "Credit Agreement"), pursuant to which
Lender has made and may hereafter make loans and advances and other extensions
of credit to Borrowers.

         B. Borrowers wish, and Lender is willing, to amend certain provisions
of the Credit Agreement, all on the terms and conditions set forth in this
Amendment.

         C. This Amendment shall constitute a Loan Document and these Recitals
shall be construed as part of this Amendment. Capitalized terms used herein
without definition are so used as defined in Annex A to the Credit Agreement.

         NOW, THEREFORE, in consideration of the premises and the mutual
covenants hereinafter contained, the parties hereto agree as follows:

         1. Amendment of Credit Agreement. The Credit Agreement is hereby
amended as follows:

         (a) The text contained in paragraph (c) of Annex G to the Credit
Agreement is deleted in its entirety and replaced with the text "Intentionally
omitted".

         (b) Each reference to "Loan and Security Agreement" contained in that
certain Second Amendment to Credit Agreement dated as of April 22, 1998 by and
among the parties hereto is deleted and replaced with a reference to "Credit
Agreement".

         2. Representations and Warranties of Borrower. In order to induce
Lender to enter into this Amendment, Borrowers hereby jointly and severally
represent and warrant to Lender that:

         (a) No Default. After giving effect to this Amendment, no Default or
Event of Default has occurred and is continuing.
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         (b) Representations and Warranties. After giving effect to this
Amendment, all of the representations and warranties of Borrowers contained in
the Loan Documents are true, accurate and complete in all respects on and as of
the date hereof to the same extent as though made on and as of the date hereof.
(c) Authorization, etc. Each Borrower has the power and authority to execute,
deliver and perform this Amendment. Each Borrower has taken all necessary action
(including, without limitation, obtaining approval of its stockholders, if
necessary) to authorize its execution, delivery and performance of this
Amendment. No consent, approval or authorization of, or declaration or filing
with, any Governmental Authority, and no consent of any other Person, is
required in connection with any Borrower's execution, delivery and performance
of this Amendment, except for those already duly obtained. This Amendment has
been duly executed and delivered by each Borrower and constitutes the legal,
valid and binding obligation of each Borrower, enforceable against it in
accordance with its terms. Each Borrower's execution, delivery and performance
of this Amendment does not conflict with, or constitute a violation or breach
of, or constitute a default under, or result in the creation or imposition of
any Lien upon the property of such Borrower by reason of the terms of (a) any
contract, mortgage, lease, agreement, indenture or instrument to which any
Borrower is a party or which is binding upon it, (b) any law or regulation or
order or decree of any court applicable to any Borrower, or (c) the certificate
or articles of incorporation or by-laws of any Borrower.

         3. Conditions to Effectiveness. The effectiveness of this Amendment is
expressly conditioned upon the satisfaction of each condition set forth in this
Section 3 and the delivery of the following documents to Lender on or prior to
the date hereof and consummation of all of the transactions contemplated by each
such document, all in form and substance acceptable to Lender in its sole and
absolute discretion:

         (a) Documentation. Borrowers shall have delivered to Lender all of the
following documents:

                  (i) Amendment. Duly executed originals of this Amendment.

                  (ii) Other Documents. All other documents, certificates and
         agreements as the Lender may reasonably request to accomplish the
         purposes of this Amendment.

         (b) No Default. As of the date hereof after giving effect to this
Amendment, no Default or Event of Default shall have occurred and be continuing.

         (c) Warranties and Representations. After giving effect to this
Amendment, all of the warranties and representations of Borrowers contained in
the Credit Agreement and the other Loan Documents (including, without
limitation, this Amendment) shall be true and correct in all material respects
to the same extent as though made on and as of the date hereof.


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         (d) Consents and Acknowledgments. Borrowers shall have obtained all
consents, approvals and acknowledgments which may be required with respect to
the execution, delivery and performance of this Amendment.

         (e) Fees, Costs and Expenses. Lender shall have received payment of all
fees, costs and expenses, including, without limitation, reasonable attorneys'
fees and expenses invoiced to Borrower Representative and as otherwise due
pursuant to the Loan Documents, incurred by Lender in connection herewith.

         4. Reference to and Effect on Loan Documents.

         4.1 Ratification. Except as specifically amended above, the Credit
Agreement and the other Loan Documents shall remain in full force and effect and
each Borrower hereby ratifies and confirms each such Loan Document.

         4.2 No Waiver. The execution, delivery and effectiveness of this
Amendment shall not operate as a waiver of any right, power or remedy of Lender
under the Credit Agreement or any of the other Loan Documents, or, except as
expressly provided herein, constitute a consent, waiver or modification with
respect to any provision of the Credit Agreement or any of the other Loan
Documents. Upon the effectiveness of this Amendment each reference in (a) the
Credit Agreement to "this Agreement," "hereunder," "hereof," or words of similar
import and (b) any other Loan Document to "the Agreement" shall, in each case
and except as otherwise specifically stated therein, mean and be a reference to
the Credit Agreement as amended hereby.

         5. Affirmation of Subsidiary Guarantee. Safer Canada (a) consents to
and approves the execution and delivery of this Amendment by Borrowers and
Lender, (b) agrees that this Amendment does not and shall not limit or diminish
in any manner its obligations under the Subsidiary Guarantee or under any of the
other Loan Documents executed and/or delivered by it in connection therewith,
(c) agrees that this Amendment shall not be construed as requiring the consent
of Safer Canada in any other circumstance, (d) reaffirms its obligations under
the Subsidiary Guarantee and all of the other Loan Documents to which it is a
party, and (e) agrees that the Subsidiary Guarantee and such other Loan
Documents remain in full force and effect and are each hereby ratified and
confirmed.

         6. Miscellaneous.

         6.1 Successors and Assigns. This Amendment shall be binding on and
shall inure to the benefit of Borrowers, Lender and their respective successors
and assigns, except as otherwise provided herein. No Credit Party may assign,
transfer, hypothecate or otherwise convey its rights, benefits, obligations or
duties hereunder without the prior express written consent of Agent and Lenders.
The terms and provisions of this Amendment are for the purpose of defining the
relative rights and obligations of Borrowers and Lender with respect to the
transactions contemplated hereby and there shall be no third party beneficiaries
of any of the terms and provisions of this Amendment.


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         6.2 Entire Agreement. This Amendment, including all schedules and other
documents attached hereto or incorporated by reference herein or delivered in
connection herewith, constitutes the entire agreement of the parties with
respect to the subject matter hereof and supersedes all other understandings,
oral or written, with respect to the subject matter hereof.

         6.3 Fees and Expenses. As provided in Section 11.3 of the Credit
Agreement, Borrowers agree to pay on demand all fees, costs and expenses
incurred by the Lender in connection with the preparation, execution and
delivery of this Amendment.

         6.4 Headings. Section headings in this Amendment are included herein
for convenience of reference only and shall not constitute a part of this
Amendment for any other purpose.

         6.5 Severability. Wherever possible, each provision of this Amendment
shall be interpreted in such a manner as to be effective and valid under
applicable law, but if any provision of this Amendment shall be prohibited by or
invalid under applicable law, such provision shall be ineffective to the extent
of such prohibition or invalidity, without invalidating the remainder of such
provision or the remaining provisions of this Amendment.

         6.6 Conflict of Terms. Except as otherwise provided in this Amendment,
if any provision contained in this Amendment is in conflict with, or
inconsistent with, any provision in any of the other Loan Documents, the
provision contained in this Amendment shall govern and control.

         6.7 Counterparts. This Amendment may be executed in any number of
separate counterparts, each of which shall collectively and separately
constitute one agreement. Delivery of an executed counterpart of a signature
page to this Amendment by telecopy shall be effective as delivery of a manually
executed counterpart of this Amendment.

         6.8 Incorporation of Credit Agreement. The provisions contained in
Sections 11.9 and 11.13 of the Credit Agreement are incorporated herein by
reference to the same extent as if reproduced herein in their entirety.

         6.9 Acknowledgment. Each Credit Party hereby represents and warrants
that there are no liabilities, claims, suits, debts, liens, losses, causes of
action, demands, rights, damages or costs, or expenses of any kind, character or
nature whatsoever, known or unknown, fixed or contingent (collectively, the
"Claims"), which any Credit Party may have or claim to have against Lender, or
any of their respective affiliates, agents, employees, officers, directors,
representatives, attorneys, successors and assigns (collectively, the "Lender
Released Parties"), which might arise out of or be connected with any act of
commission or omission of the Lender Released Parties existing or occurring on
or prior to the date of this Amendment, including, without limitation, any
Claims arising with respect to the Obligations or any Loan Documents. In
furtherance of the foregoing, each Credit Party hereby releases, acquits and
forever discharges the Lender Released Parties from any and all Claims that any
Credit Party may have or claim to have, relating to or arising out of or in
connection with the Obligations or any Loan Documents or any other agreement


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or transaction contemplated thereby or any action taken in connection therewith
from the beginning of time up to and including the date of the execution and
delivery of this Amendment. Each Credit Party further agrees forever to refrain
from commencing, instituting or prosecuting any lawsuit, action or other
proceeding against any Lender Released Parties with respect to any and all
Claims.

                            [signature pages follow]



                                        5
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         IN WITNESS WHEREOF, this Third Amendment to Credit Agreement has been
duly executed as of the date first written above.

                                              RINGER CORPORATION


                                              By:/S/ Mark Eisenschenk        
                                                 ------------------------------
                                              Title: Executive Vice President
                                                     --------------------------


                                              SAFER, INC.


                                              By: /S/ Mark Eisenschenk       
                                                 ------------------------------
                                              Title: Executive Vice President
                                                     --------------------------


                                              SURECO, INC.


                                              By: /S/ Mark Eisenschenk       
                                                 ------------------------------
                                              Title: Secretary               
                                                     --------------------------


                                              GENERAL ELECTRIC CAPITAL
                                              CORPORATION, as Lender


                                              By: /S/ Trevor Clark
                                                  -----------------------------
                                              Title: Vice President
                                                     --------------------------
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         Each of the following Persons is a signatory to this Third Amendment to
Credit Agreement in its capacity as a Credit Party and not as a Borrower.

                                              SAFER, INC.


                                              By: /S/ Mark Eisenschenk       
                                                  -----------------------------
                                              Title: Executive Vice President
                                                     --------------------------


                                              SOUTHERN RESOURCES, INC.


                                              By: /S/ Mark Eisenschenk       
                                                  -----------------------------
                                              Title: Secretary               
                                                     --------------------------