12. SUBSEQUENT EVENTS	6 Months Ended
Oct. 31, 2015
Subsequent Events [Abstract]
12. SUBSEQUENT EVENTS	Sale of Common Stock August 2015 AMI Sales Agreement - Subsequent to October 31, 2015 and through December 10, 2015, we sold 1,939,413 shares of common stock at market prices under the August 2015 AMI Sales Agreement (Note 6) for aggregate gross proceeds of $2,261,000. As of December 10, 2015, aggregate gross proceeds of up to $22,553,000 remained available to us under the August 2015 AMI Sales Agreement. Equity Distribution Agreement - Subsequent to October 31, 2015 and through December 10, 2015, we sold 1,925,844 shares of common stock at market prices under the Equity Distribution Agreement (Note 6) for aggregate gross proceeds of $2,371,000. As of December 10, 2015, aggregate gross proceeds of up to $17,629,000 remained available to us under the Equity Distribution Agreement. Series E Preferred Stock Dividend On December 7, 2015, our Board of Directors declared a quarterly cash dividend of $0.65625 per share on our Series E Preferred Stock. The dividend payment is equivalent to an annualized 10.50% per share, based on the $25.00 per share stated liquidation preference, accruing from October 1, 2015 through December 31, 2015. The cash dividend is payable on January 4, 2016 to holders of the Series E Preferred Stock of record on December 18, 2015.

12. SUBSEQUENT EVENTS

6 Months Ended

Oct. 31, 2015

Sale of Common Stock

August 2015 AMI Sales Agreement - Subsequent to October 31, 2015 and through December 10, 2015, we sold 1,939,413 shares of common stock at market prices under the August 2015 AMI Sales Agreement (Note 6) for aggregate gross proceeds of $2,261,000. As of December 10, 2015, aggregate gross proceeds of up to $22,553,000 remained available to us under the August 2015 AMI Sales Agreement.

Equity Distribution Agreement - Subsequent to October 31, 2015 and through December 10, 2015, we sold 1,925,844 shares of common stock at market prices under the Equity Distribution Agreement (Note 6) for aggregate gross proceeds of $2,371,000. As of December 10, 2015, aggregate gross proceeds of up to $17,629,000 remained available to us under the Equity Distribution Agreement.

Series E Preferred Stock Dividend

On December 7, 2015, our Board of Directors declared a quarterly cash dividend of $0.65625 per share on our Series E Preferred Stock. The dividend payment is equivalent to an annualized 10.50% per share, based on the $25.00 per share stated liquidation preference, accruing from October 1, 2015 through December 31, 2015. The cash dividend is payable on January 4, 2016 to holders of the Series E Preferred Stock of record on December 18, 2015.