Subscription Agreement

1.

As of the Closing (as defined below) and subject to the terms and conditions hereof, the Investor will purchase from the Company and the Company will issue and sell to the Investor (i) such number of shares (the “ Shares ”) of common stock of the Company, par value $0.001 per share (the “ Common Stock ”), and (ii) such number of warrants (the “ Warrants ”) to purchase shares of Common Stock, in such number of units (the “ Units ”), with each Unit consisting of (a) one share of Common Stock and (b) one Warrant to purchase 0.40 of a share of Common Stock (the “ Warrant Ratio ”), as is set forth on the signature page hereto (the “ Signature Page ”) for a purchase price of $2.20 per Unit.

2.

The closing is expected to occur on or about August 25, 2009 (the “ Closing ”) in accordance with Rule 15c6-1 promulgated under the Securities Exchange Act of 1934, as amended, subject to the satisfaction of certain closing conditions set forth in the Placement Agency Agreement dated as of August 19, 2009 (the “ Placement Agency Agreement ”) entered into by and between the Company and the placement agent for the Offering (as defined below). At the Closing, (a) the Company shall cause the Company’s transfer agent for the Common Stock to electronically deliver to the Investor through DTC the number of Shares set forth on the signature page registered in the name of the Investor or, if so indicated on the signature page, in the name of a nominee designated by the Investor, (b) the Company shall cause to be delivered to the Investor a Warrant to purchase a number of whole shares of Common Stock determined by multiplying the number of Shares set forth on the signature page by the Warrant Ratio and rounding down to the nearest whole number and (c) the aggregate purchase price for the Units being purchased by the Investor will be delivered by or on behalf of the Investor to the Company.

3.

The offering and sale of the Units (the “ Offering ”) is being made pursuant to (i) an effective registration statement on Form S-3 (File No. 333-154842), including the prospectus contained therein (the “ Base Prospectus ”), filed with the Securities and Exchange Commission (the “ Commission ”) on October 30, 2008, (ii) an automatically effective registration statement (File No. 333-161214) registering the rights issuable under the Company’s Stockholder Rights Plan, dated November 3, 1999, filed with the Commission pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the “ Securities Act ”), on August 10, 2009, and (iii) a final prospectus supplement (the “ Prospectus Supplement ”) containing certain supplemental information regarding the Units and terms of the Offering. The Base Prospectus has been delivered to the Investor on or prior to the date hereof and has been filed with the Commission in accordance with applicable securities laws. The Base Prospectus, together with the documents incorporated by reference therein and the pricing information set forth in Schedule I to this Subscription Agreement, are collectively referred to herein as the “ General Disclosure Package .”

4.

The Company’s obligation to issue and sell the Units to the Investor shall be subject to the receipt by the Company of the purchase price for the Units being purchased hereunder as set forth on the Signature Page and the accuracy of the representations and warranties made by the Investor herein

and the fulfillment of those undertakings herein of the Investor to be fulfilled prior to the Closing Date. The Investor’s obligation to purchase the Units shall be subject to the condition that the placement agent shall not have (i) terminated the Placement Agency Agreement pursuant to the terms thereof or (ii) determined that the conditions to closing in the Placement Agency Agreement have not been satisfied.

5.

The Company shall before the opening of trading on the Nasdaq Global Market on the next trading day after the date hereof, issue a press release and file a Current Report on Form 8-K, together disclosing all material aspects of the transactions contemplated hereby and attaching thereto the form of Subscription Agreement and form of Warrant for this Offering. The Company shall not identify the Investor by name in any press release or public filing, or otherwise publicly disclose the Investor’s name, without the Investor’s prior written consent, unless required by applicable laws, rules and regulations.

6.

The Investor represents that (i) it has had full access to the General Disclosure Package prior to or in connection with its receipt of this Subscription Agreement and is relying only on such information and documents in making its decision to purchase the Units, and (ii) it is acquiring the Units for its own account, or an account over which it has investment discretion, and does not have any agreement or understanding, directly or indirectly, with any person or entity to distribute any of the Units.

7.

The Investor and the Company each has the requisite power and authority to enter into this Subscription Agreement and to consummate the transactions contemplated hereby.

8.

The Investor represents that neither the Investor nor any person acting on behalf of, or pursuant to any understanding with or based upon any information received from, the Investor has, directly or indirectly, as of the date of this Subscription Agreement, engaged in any purchases or sales of the securities of the Company or has violated its obligations of confidentiality with respect to the Offering since the time that the Investor was first contacted by the Company or its agents with respect to the transactions contemplated hereby. The Investor covenants that neither it, nor any person acting on behalf of, or pursuant to any understanding with or based upon any information received from, the Investor will engage in any purchases or sales of the securities of the Company prior to the time that the transactions contemplated by this Subscription Agreement are publicly disclosed pursuant to Section 5 hereof. Notwithstanding the foregoing, in the case of an Investor and/or its affiliates that is, individually or collectively, a multi-managed investment bank or vehicle whereby separate portfolio managers manage separate portions of such Investor’s or affiliates assets and the portfolio managers have no direct knowledge of the investment decisions made by the portfolio managers managing other portions of such Investor’s or affiliates assets, the representation set forth above shall only apply with respect to the portion of assets managed by the portfolio