2. STOCK-BASED COMPENSATION (Details 4) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
Nov. 30, 2012	Aug. 31, 2012	May 31, 2012
Range Exercise Prices Options Outstanding Minimum	$ 0.59
Range Exercise Prices Options Outstanding Maximum	$ 9.94
Number of Options Outstanding, Ending	2,982,000	2,893,000	2,957,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	4 years 1 month
Weighted Average Exercise Price Outstanding, Ending	$ 1.87	$ 2.00	$ 2.40
Number Exercisable Shares	1,603,000
Weighted Average Remaining Contractual Life (Years)	2 years 7 months
Weighted Average Exercise Price Options Excercisable	$ 2.50
Aggregate Intrinsic Value	$ 51
Options Price Range A
Range Exercise Prices Options Outstanding Minimum	$ 0.59
Range Exercise Prices Options Outstanding Maximum	$ 0.97
Number of Options Outstanding, Ending	1,135,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	4 years 6 months
Weighted Average Exercise Price Outstanding, Ending	$ 0.75
Number Exercisable Shares	638,000
Weighted Average Remaining Contractual Life (Years)	3 years 1 month
Weighted Average Exercise Price Options Excercisable	$ 0.82
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	1,606,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	4 years 3 months
Weighted Average Exercise Price Outstanding, Ending	$ 1.57
Number Exercisable Shares	724,000
Weighted Average Remaining Contractual Life (Years)	2 years 11 months
Weighted Average Exercise Price Options Excercisable	$ 1.79
Options Price Range C
Range Exercise Prices Options Outstanding Minimum	$ 6.00
Range Exercise Prices Options Outstanding Maximum	$ 9.30
Number of Options Outstanding, Ending	127,000
Weighted Average Remaining Contractual Life (Years) Options Outstanding	7 months
Weighted Average Exercise Price Outstanding, Ending	$ 8.34
Number Exercisable Shares	127,000
Weighted Average Remaining Contractual Life (Years)	7 months
Weighted Average Exercise Price Options Excercisable	$ 8.34
Options Price Range D
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	7 months
Weighted Average Exercise Price Outstanding, Ending	$ 9.94
Number Exercisable Shares	114,000
Weighted Average Remaining Contractual Life (Years)	7 months
Weighted Average Exercise Price Options Excercisable	$ 9.94

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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