2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details - Antidilutive shares) - shares	3 Months Ended		9 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Stock Options [Member]
Antidilutive shares excluded from calculation of weighted average diluted shares outstanding	115,425	0	78,427	0
ESPP [Member]
Antidilutive shares excluded from calculation of weighted average diluted shares outstanding	1,202	5,198	466	27,661
Options and ESPP Warrants [Member]
Antidilutive shares excluded from calculation of weighted average diluted shares outstanding	116,627	5,198	78,893	27,661