BASIC AND DILUTED NET LOSS PER COMMON SHARE (Details 1) - shares	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	7,683,000	5,661,000
Common stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,328,000	3,290,000
Series H, H-1, H-2 and H-3 Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,462,000	1,076,000
Common stock purchase warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,893,000	1,295,000