Prospectus Summary
The following summary highlights information found in greater detail elsewhere in this prospectus. It may not contain all of the information that is important to you. You should read the entire prospectus, including "Risk Factors" and the financial statements and notes to those statements, before you decide to buy our common stock. Except as otherwise noted, all information in this prospectus assumes the exercise of all outstanding warrants to purchase shares of preferred stock and common stock, gives effect to the conversion of all outstanding shares of preferred stock, and assumes no exercise of the underwriters' option to purchase additional shares of common stock in the offering. The share information in this prospectus reflects the approval by our shareholders on March 17, 2000 of two common stock dividends in which, in each case, our shareholders received an additional share of our common stock for each share held by them.