2. STOCK-BASED COMPENSATION (Details 3) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Aug. 31, 2012	May 31, 2012	Aug. 31, 2011
Number of Options Outstanding, Ending	2,893,000	2,957,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	4 years 26 days
Weighted Average Exercise Price Outstanding, Ending	$ 2.00	$ 2.4
Number Exercisable Shares	1,541,000
Weighted Average Remaining Contractual Life (Years)	2 years 7 months 2 days
Weighted Average Exercise Price Options Excercisable	$ 2.70		$ 3.59
Aggregate Intrinsic Value	$ 164
Options Price Range A
Range Exercise Prices Options Outstanding Minimum	$ 0.59
Range Exercise Prices Options Outstanding Maximum	$ 0.89
Number of Options Outstanding, Ending	956,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	4 years 3 months 26 days
Weighted Average Exercise Price Outstanding, Ending	$ 0.74
Number Exercisable Shares	606,000
Weighted Average Remaining Contractual Life (Years)	3 years 1 month 29 days
Weighted Average Exercise Price Options Excercisable	$ 0.83
Options Price Range B
Range Exercise Prices Options Outstanding Minimum	$ 1.10
Range Exercise Prices Options Outstanding Maximum	$ 2.52
Number of Options Outstanding, Ending	1,633,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	4 years 6 months 19 days
Weighted Average Exercise Price Outstanding, Ending	$ 1.57
Number Exercisable Shares	631,000
Weighted Average Remaining Contractual Life (Years)	2 years 11 months 16 days
Weighted Average Exercise Price Options Excercisable	$ 1.83
Options Price Range C
Range Exercise Prices Options Outstanding Minimum	$ 3.00
Range Exercise Prices Options Outstanding Maximum	$ 3.66
Number of Options Outstanding, Ending	38,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	1 month 21 days
Weighted Average Exercise Price Outstanding, Ending	$ 3.51
Number Exercisable Shares	38,000
Weighted Average Remaining Contractual Life (Years)	1 month 21 days
Weighted Average Exercise Price Options Excercisable	$ 3.51
Options Price Range D
Range Exercise Prices Options Outstanding Minimum	$ 6.00
Range Exercise Prices Options Outstanding Maximum	$ 9.30
Number of Options Outstanding, Ending	152,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	8 months 16 days
Weighted Average Exercise Price Outstanding, Ending	$ 8.17
Number Exercisable Shares	152,000
Weighted Average Remaining Contractual Life (Years)	8 months 16 days
Weighted Average Exercise Price Options Excercisable	$ 8.17
Options Price Range E
Range Exercise Prices Options Outstanding Minimum	$ 9.94
Range Exercise Prices Options Outstanding Maximum	$ 9.94
Number of Options Outstanding, Ending	114,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	9 months 22 days
Weighted Average Exercise Price Outstanding, Ending	$ 9.94
Number Exercisable Shares	114,000
Weighted Average Remaining Contractual Life (Years)	9 months 22 days
Weighted Average Exercise Price Options Excercisable	$ 9.94