<PAGE>
EXHIBIT B
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SCHEDULE 13D JOINT FILING AGREEMENT
The undersigned and each other person executing this joint filing agreement
(this "Agreement") agree as follows:
(i) The undersigned and each other person executing this Agreement are
individually eligible to use the Schedule 13D to which this Exhibit is attached
and such Schedule 13D is filed on behalf of the undersigned and each other
person executing this Agreement; and
(ii) The undersigned and each other person executing this Agreement are
responsible for the timely filing of such Schedule 13D and any amendments
thereto, and for the completeness and accuracy of the information concerning
such person contained therein; but none of the undersigned or any other person
executing this Agreement is responsible for the completeness or accuracy of the
information statement concerning any other persons making the filing, unless
such person knows or has reason to believe that such information is inaccurate.
This Agreement may be executed in any number of counterparts, each of which
shall be deemed to be an original, but all of which, taken together, shall
constitute one and the same instrument.
* * * * * *
Page 29 of 31 Pages
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In Witness Whereof, the undersigned have caused this Agreement to be signed
by their respective officers thereunto duly authorized as of August 21, 2000.
LEHMAN BROTHERS HOLDINGS INC.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Vice President and Secretary
LEHMAN BROTHERS INC.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Senior Vice President and Secretary
LB I GROUP INC.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Secretary
LEHMAN BROTHERS VENTURE CAPITAL PARTNERS I, L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
LEHMAN BROTHERS VENTURE ASSOCIATES INC.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Vice President and Secretary
LEHMAN BROTHERS VENTURE GP PARTNERSHIP, L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
LEHMAN BROTHERS VENTURE PARTNERS, L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
<PAGE>
LEHMAN BROTHERS 1999 VENTURE GP PARTNERSHIP L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
LEHMAN BROTHERS VC PARTNERS L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
LEHMAN BROTHERS MBG VENTURE CAPITAL PARTNERS 1998
(A) L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
LEHMAN BROTHERS MBG VENTURE CAPITAL PARTNERS 1998
(B) L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
LEHMAN BROTHERS MBG VENTURE CAPITAL PARTNERS 1998
(C) L.P.
By: /s/ Jennifer Marre
---------------------------------------------
Name: Jennifer Marre
Title: Authorized Signatory
Page 31 of 31 Pages
