7. EQUITY COMPENSATION PLANS (Details 1) (USD $)	12 Months Ended
Apr. 30, 2013
Number of Options
Number of Options Outstanding, Beginning	7,531,651
Number of Options Granted	8,677,208
Number of Options Exercised	(118,555)
Number of Options Cancelled or Expired	(803,096)
Number of Options Outstanding, Ending	15,287,208
Exercisable and expected to vest	15,086,905
Exercisable, April 30, 2013	7,434,607
Weighted Average Exercise Price
Weighted Average Exercise Price Outstanding, Beginning	$ 2.9
Weighted Average Exercise Price Granted	$ 0.88
Weighted Average Exercise Price Exercised	$ 0.83
Weighted Average Exercise Price Canceled	$ 1.58
Weighted Average Exercise Price Outstanding, Ending	$ 1.84
Weighted Average Exercise Price, Exercisable and expected to vest	$ 1.85
Weighted Average Exercise Price Exercisable, April 30, 2013	$ 2.67
Weighted Average Remaining Contractual Life (in years)
Weighted Average Remaining Contractual Life (in years) Outstanding, Beginning	8 years 25 days
Weighted Average Remaining Contractual Life (in years) Vested and expected to vest	8 years 18 days
Weighted Average Remaining Contractual Life (in years) Exercisable, April 30, 2013	6 years 10 months 10 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value Outstanding	$ 5,294,000
Aggregate Intrinsic Value vested and expected to vest	5,228,000
Aggregate Intrinsic Value Exercisable, April 30, 2013	$ 1,811,000

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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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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable.

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The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date.

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As of the balance sheet date, the weighted-average exercise price (at which grantees can acquire the shares reserved for issuance) for exercisable stock options that are fully vested or expected to vest.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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

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Number of share options (or share units) exercised during the current period.

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