<PAGE>

            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSTITUTE FORM W-9

Guidelines for Determining the Proper Identification Number for the Payee (You)
to Give the Payer.--Social security numbers have nine digits separated by two
hyphens: i.e., 000-00-0000. Employee identification numbers have nine digits
separated by only one hyphen: i.e., 00-0000000. The table below will help
determine the number to give the payer. All "Section" references are to the
Internal Revenue Code of 1986, as amended. "IRS" is the Internal Revenue
Service.



<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
                                   GIVE THE                                                         GIVE THE
                                   SOCIAL                                                           EMPLOYER
FOR THIS TYPE OF ACCOUNT:          SECURITY                      FOR THIS TYPE OF ACCOUNT:          IDENTIFICATION
                                   NUMBER OF--                                                      NUMBER OF--
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                <C>                           <C>                                <C>
1. Individual                      The Individual                6. Sole proprietorship             The owner(3)

2. Two or more individuals         The actual owner of the       7. A valid trust, estate,          The legal entity(4)
   (joint account)                 account or, if combined          or pension trust
                                   funds, the first individual
                                   on the account(1)             8. Corporate                       The corporation


3. Custodian account of a          The minor(2)                  9. Association, club, religious,   The organization
   minor (Uniform Gift to                                           charitable, educational, or
   Minors Act)                                                      other tax-exempt organization

4. a. The usual revocable          The grantor-trustee(1)       10. Partnership                     The partnership
      savings trust account
      (grantor is also trustee)                                 11. A broker or registered          The broker or nominee
                                                                    nominee

   b. So-called trust account      The actual owner(1)          12. Account with the Department     The public entity
      that is not a legal or valid                                  of Agriculture in the name of
      trust under state law                                         a public entity (such as a
                                                                    state or local government,
5. Sole proprietorship             The owner(3)                     school district, or prison)
                                                                    that receives agricultural
                                                                    program payments
</TABLE>


1     List first and circle the name of the person whose number you furnish. If
      only one person on a joint account has a social security number, that
      person's number must be furnished.

2     Circle the minor's name and furnish the minor's social security number.

3     You must show your individual name, but you may also enter your business
      or "doing business as" name. You may use either your social security
      number of your employer identification number (if you have one).

4     List first and circle the name of the legal trust, estate, or pension
      trust. (Do not furnish the taxpayer identification number of the personal
      representative or trustee unless the legal entity itself is not designated
      in the account title.)

      NOTE:
      If no name is circled when there is more than one name, the number will be
      considered to be that of the first name listed.

<PAGE>

            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSITITUTE FORM W-9

OBTAINING A NUMBER

If you don't have a taxpayer identification number or you don't know your
number, obtain Form SS-5, Application for a Social Security Card, at the local
Social Administration office, or Form SS-4, Application for Employer
Identification Number, by calling 1 (800) TAX-FORM, and apply for a number.

PAYEES EXEMPT FROM BACKUP WITHHOLDING


Payees specifically exempted from withholding include:

 o An organization exempt from tax under Section 501(a), an individual
   retirement account (IRA), or a custodial account under Section 403(b)(7),
   if the account satisfies the requirements of Section 401(f)(2).

 o The United States or a state thereof, the District of Columbia, a possession
   of the United States, or a political subdivision or instrumentality of any
   one or more of the foregoing.

 o An international organization or any agency or instrumentality thereof.

 o A foreign government and any political subdivision, agency or
   instrumentality thereof.


Payees that may be exempt from backup withholding include:

 o A corporation.

 o A financial institution.

 o A dealer in securities or commodities required to register in the United
   States, the District of Columbia, or a possession of the United States.

 o A real estate investment trust.

 o A common trust fund operated by a bank under Section 584(a).

 o An entity registered at all times during the tax year under the Investment
   Company Act of 1940.

 o A middleman known in the investment community as a nominee or custodian.

 o A futures commission merchant registered with the Commodity Futures Trading
   Commission.

 o A foreign central bank of issue.

 o A trust exempt from tax under Section 664 or described in Section 4947.


Payments of dividends and patronage dividends generally exempt from backup
withholding include:

 o Payments to nonresident aliens subject to withholding under Section 1441.

 o Payments to partnerships not engaged in a trade or business in the United
   States and that have at least one nonresident alien partner.

 o Payments of patronage dividends not paid in money.

 o Payments made by certain foreign organizations.

 o Section 404(k) payments made by an ESOP.

Payments of interest generally exempt from backup withholding include:

 o Payments of interest on obligations issued by individuals. Note: You may be
   subject to backup withholding if this interest is $600 or more and you have
   not provided your correct taxpayer identification number to the payer.


 o Payments of tax-exempt interest (including exempt-interest dividends under
   Section 852).


 o Payments described in Section 6049(b)(5) to nonresident aliens.


 o Payments on tax-free covenant bonds under Section 1451.


 o Payments made by certain foreign organizations.


 o Mortgage interest paid to you.


Certain payments, other than payments of interest, dividends, and patronage
dividends, that are exempt from information reporting are also exempt from
backup withholding. For details, see the regulations under sections 6041,
6041A, 6042, 6044, 6045, 6049, 6050A and 6050N.


EXEMPT PAYEES DESCRIBED ABOVE MUST FILE FORM W-9 OR A SUBSTITUTE FORM W-9 TO
AVOID POSSIBLE ERRONEOUS BACKUP WITHHOLDING. FILE THIS FORM WITH THE PAYER,
FURNISH YOUR TAXPAYER IDENTIFICATION NUMBER, WRITE "EXEMPT" IN PART II OF THE
FORM, SIGN AND DATE THE FORM, AND RETURN IT TO THE PAYER.


PRIVACY ACT NOTICE--Section 6109 requires you to provide your correct taxpayer
identification number to payers, who must report the payments to the IRS. The
IRS uses the number for identification purposes and may also provide this
information to various government agencies for tax enforcement or litigation
purposes. Payers must be given the numbers whether or not recipients are
required to file tax returns. Payers must generally withhold up to 30% of
taxable interest, dividends, and certain other payments to a payee who does not
furnish a taxpayer identification number to payer. Certain penalties may also
apply.

PENALTIES

(1) FAILURE TO FURNISH TAXPAYER IDENTIFICATION NUMBER.--If you fail to furnish
your taxpayer identification number to a payer, you are subject to a penalty of
$50 for each such failure unless your failure is due to reasonable cause and
not to willful neglect.

(2) CIVIL PENALTY FOR FALSE INFORMATION WITH RESPECT TO WITHHOLDING.--If you
make a false statement with no reasonable basis that results in no backup
withholding, you are subject to a $500 penalty.

(3) CRIMINAL PENALTY FOR FALSIFYING INFORMATION.--Willfully falsifying
certifications or affirmations may subject you to criminal penalties including
fines and/or imprisonment.

FOR ADDITIONAL INFORMATION CONTACT YOUR TAX CONSULTANT OR THE INTERNAL REVENUE
SERVICE.


