2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details - Antidilutive shares) - shares	12 Months Ended
Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Dilutive effect of shares on diluted shares outstanding	2,029,713	3,880,185	4,652,810
Stock Options
Dilutive effect of shares on diluted shares outstanding	1,764,684	3,833,193	4,576,112
Employee Stock Purchase Plan [Member]
Dilutive effect of shares on diluted shares outstanding	265,029	46,992	72,896
Warrants
Dilutive effect of shares on diluted shares outstanding	0	0	3,802

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Antidilution
-URI http://asc.fasb.org/extlink&oid=6505113

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Diluted Earnings Per Share
-URI http://asc.fasb.org/extlink&oid=6510752

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Contingent Stock Agreement
-URI http://asc.fasb.org/extlink&oid=6508534

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration