10. CAPITAL STOCK (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011
Available Shares Stock Option Tranactions
Available Shares, Beginning	839	687	998
Additional shares reserved	1,223	1,199
Options granted	(670)	(1,141)	(508)
Options terminated	569	258	327
Plan shares expired	(224)	(164)	(130)
Available Shares, Ending	1,737	839	687
Outstanding Options Stock Option Tranactions
Options Outstanding, Beginning	2,957	2,083	1,949
Options Granted	670	1,141	508
Options terminated	(569)	(258)	(327)
Plan options exercised	(102)	(9)	(47)
Number of Options Outstanding, Ending	2,956	2,957	2,083
Options exercisable and expected to be exercisable	2,897
Weighted Average Exercise Price Outstanding, Beginning	$ 2.40	$ 3.40	$ 3.88
Weighted Average Exercise Price Granted	$ 1.13	$ 0.92	$ 1.88
Weighted Average Exercise Price Terminated	$ 4.37	$ 3.72	$ 4.30
Weighted Average Exercise Price Exercised	$ 0.67	$ 0.85	$ 0.85
Weighted Average Exercise Price Outstanding, Ending	$ 1.79	$ 2.40	$ 3.40
Weighted Average Exercise Price Exercisable and expected to be exercisable	$ 1.79
Aggregate Intrinsic Value, beginning balance	$ 587	$ 298	$ 833
Aggregate Intrinsic Value, ending balance	964	587	298
Aggregate Intrinsic Value for Options fully vested and expected to vest	$ 945