2. STOCK-BASED COMPENSATION (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
Stock-Based Compensation Details 2
Available Shares, Beginning (in thousands)	1,737
Options granted (in thousands)	(725)
Options terminated (in thousands)	289
Plan shares expired (in thousands)	(104)
Available Shares, Ending (in thousands)	1,197
Options Outstanding, Beginning (in thousands)	2,956
Options Granted (in thousands)	725
Options terminated (in thousands)	(289)
Plan options exercised (in thousands)	(69)
Number of Options Outstanding, Ending (in thousands)	3,323
Weighted Average Exercise Price Outstanding, Beginning	$ 1.79
Weighted Average Exercise Price Granted	$ 1.38
Weighted Average Exercise Price Terminated	$ 6.99
Weighted Average Exercise Price Exercised	$ 0.86
Weighted Average Exercise Price Outstanding, Ending	$ 1.27
Aggregate Intrinsic Value, beginning balance	$ 964
Aggregate Intrinsic Value, ending balance	1,301
Options fully vested and expected to vest at August 31, 2013 (in thousands)	3,257
Options exercisable at August 31, 2013 (in thousands)	1,816	1,541
Weighted Average Exercise Price for Options fully vested and expected to vest at August 31, 2013	$ 1.27
Weighted Average Exercise Price for Options exercisable at August 31, 2013	$ 1.28	$ 2.70
Aggregate Intrinsic Value for Options fully vested and expected to vest at August 31, 2013	1,275
Options exercisable at August 31, 2013 Aggregate intrinsic value	$ 769