Note 7 - Prepaid Expenses and Other Current Assets (Details) - USD ($)	Jan. 31, 2018	Apr. 30, 2017
Details
Prepaid expenses and other current assets	$ 3,140,458	$ 4,729,865
Prepayments to suppliers	1,799,838	3,286,808
Prepayment for employees' stock-based compensation	1,022,220	1,226,668
Business related employees' advances	$ 318,400	$ 216,389