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Stock-Based Compensation (Tables)

3 Months Ended

Jun. 30, 2011

Stock-Based Compensation

Employee Stock-Based Compensation Expenses Included In Consolidated Statements Of Income

	Three months ended
	June 30,
	2011	2010
Cost of revenues	$329	$383
Research and development	660	468
Selling, general and administrative	2,477	2,727
Total	$3,466	$3,578

Schedule Of Weighted-Average Assumptions Used In The Black-Scholes Valuation Model For Stock Options Granted

	Three months ended
	June 30,
	2011	2010
Expected volatility	67.5%	66.4%
Risk-free interest rate	1.9%	2.2%
Expected life (years)	5.9	6.1
Dividend yield	None	None

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