This excerpt taken from the PPD 10-Q filed Jul 24, 2007.
Note 4 Earnings Per Share
Basic earnings per common share are computed by dividing net income by the weighted average number of shares of common stock outstanding during the respective period. Diluted earnings per common share are computed by dividing net income by the weighted average number of shares of common stock and dilutive potential common shares outstanding during the respective period. The weighted average number of common shares is increased by the number of dilutive potential common shares issuable on the exercise of options less the number of common shares assumed to have been purchased with the proceeds from the exercise of the options pursuant to the treasury stock method; those purchases are assumed to have been made at the average price of the common stock during the respective period.
Options to purchase shares of common stock are excluded from the calculation of diluted earnings per share when their inclusion would have an anti-dilutive effect on the calculation. No options were excluded for the three month and six month periods ended June 30, 2007 and 2006.