6. Net Loss per Common Share (Details - Antidilutive shares) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Dilutive effect of shares on diluted shares outstanding	347	156	232	204
Stock Options
Dilutive effect of shares on diluted shares outstanding	245	117	152	161
RSUs [Member]
Dilutive effect of shares on diluted shares outstanding	102	38	73	33
Employee Stock Purchase Plan [Member]
Dilutive effect of shares on diluted shares outstanding	0	1	7	10