CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($)
   | 
Common Stock  | 
Paid-In Capital  | 
Accumulated Deficit  | 
Other Comprehensive Income (Loss)  | 
Total  | 
| Beginning balance, shares at Apr. 30, 2017 | 
905,349,047
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance, amount at Apr. 30, 2017 | 
$ 90,534
 | 
$ 97,130,279
 | 
$ (89,135,302)
 | 
$ 1,736
 | 
$ 8,087,247
 | 
| Shares issued for compensation | 
 
 | 
171,600
 | 
 
 | 
 
 | 
171,600
 | 
| Shares issued for services, shares | 
5,450,000
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Shares issued for services, amount | 
$ 545
 | 
93,946
 | 
 
 | 
 
 | 
94,491
 | 
| Shares issued for cash, net of issuance costs, shares | 
62,368,764
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Shares issued for cash, net of issuance costs, amount | 
$ 6,238
 | 
1,745,171
 | 
 
 | 
 
 | 
1,751,409
 | 
| Stock options granted | 
 
 | 
244,701
 | 
 
 | 
 
 | 
244,701
 | 
| Foreign currency translation adjustment | 
 
 | 
 
 | 
 
 | 
(1,718)
 | 
(1,718)
 | 
| Net loss | 
 
 | 
 
 | 
(1,688,415)
 | 
 
 | 
(1,688,415)
 | 
| Ending balance, shares at Jul. 31, 2017 | 
973,167,811
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance, amount at Jul. 31, 2017 | 
$ 97,317
 | 
99,385,697
 | 
(90,823,717)
 | 
18
 | 
8,659,315
 | 
| Beginning balance, shares at Apr. 30, 2017 | 
905,349,047
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance, amount at Apr. 30, 2017 | 
$ 90,534
 | 
97,130,279
 | 
(89,135,302)
 | 
1,736
 | 
8,087,247
 | 
| Foreign currency translation adjustment | 
 
 | 
 
 | 
 
 | 
 
 | 
(1,471)
 | 
| Net loss | 
 
 | 
 
 | 
 
 | 
 
 | 
(3,502,713)
 | 
| Ending balance, shares at Oct. 31, 2017 | 
973,167,811
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance, amount at Oct. 31, 2017 | 
$ 97,367
 | 
99,888,792
 | 
(92,638,015)
 | 
265
 | 
7,348,409
 | 
| Beginning balance, shares at Jul. 31, 2017 | 
973,167,811
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance, amount at Jul. 31, 2017 | 
$ 97,317
 | 
99,385,697
 | 
(90,823,717)
 | 
18
 | 
8,659,315
 | 
| Shares issued for compensation | 
 
 | 
171,600
 | 
 
 | 
 
 | 
171,600
 | 
| Shares issued for services, shares | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Shares issued for services, amount | 
$ 50
 | 
86,400
 | 
 
 | 
 
 | 
86,450
 | 
| Stock options granted | 
 
 | 
245,095
 | 
 
 | 
 
 | 
245,095
 | 
| Foreign currency translation adjustment | 
 
 | 
 
 | 
 
 | 
247
 | 
247
 | 
| Net loss | 
 
 | 
 
 | 
(1,814,298)
 | 
 
 | 
(1,814,298)
 | 
| Ending balance, shares at Oct. 31, 2017 | 
973,167,811
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance, amount at Oct. 31, 2017 | 
$ 97,367
 | 
99,888,792
 | 
(92,638,015)
 | 
265
 | 
7,348,409
 | 
| Beginning balance, shares at Apr. 30, 2018 | 
1,013,260,644
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance, amount at Apr. 30, 2018 | 
$ 101,326
 | 
101,636,215
 | 
(95,964,143)
 | 
(4,709)
 | 
5,768,689
 | 
| Shares issued for compensation | 
 
 | 
92,070
 | 
 
 | 
 
 | 
92,070
 | 
| Shares issued for services, amount | 
 
 | 
45,800
 | 
 
 | 
 
 | 
45,800
 | 
| Shares issued for cash, net of issuance costs, shares | 
66,239,316
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Shares issued for cash, net of issuance costs, amount | 
$ 6,624
 | 
1,388,376
 | 
 
 | 
 
 | 
1,395,000
 | 
| Stock options granted | 
 
 | 
113,225
 | 
 
 | 
 
 | 
113,225
 | 
| Foreign currency translation adjustment | 
 
 | 
 
 | 
 
 | 
(1,273)
 | 
(1,273)
 | 
| Net loss | 
 
 | 
 
 | 
(1,215,363)
 | 
 
 | 
(1,215,363)
 | 
| Ending balance, shares at Jul. 31, 2018 | 
1,079,499,960
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance, amount at Jul. 31, 2018 | 
$ 107,950
 | 
103,275,686
 | 
(97,179,506)
 | 
(5,982)
 | 
6,198,148
 | 
| Beginning balance, shares at Apr. 30, 2018 | 
1,013,260,644
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance, amount at Apr. 30, 2018 | 
$ 101,326
 | 
101,636,215
 | 
(95,964,143)
 | 
(4,709)
 | 
5,768,689
 | 
| Foreign currency translation adjustment | 
 
 | 
 
 | 
 
 | 
 
 | 
(7,331)
 | 
| Net loss | 
 
 | 
 
 | 
 
 | 
 
 | 
(2,251,937)
 | 
| Ending balance, shares at Oct. 31, 2018 | 
1,081,449,960
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance, amount at Oct. 31, 2018 | 
$ 108,145
 | 
103,524,179
 | 
(98,216,080)
 | 
(12,040)
 | 
5,404,204
 | 
| Beginning balance, shares at Jul. 31, 2018 | 
1,079,499,960
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance, amount at Jul. 31, 2018 | 
$ 107,950
 | 
103,275,686
 | 
(97,179,506)
 | 
(5,982)
 | 
6,198,148
 | 
| Shares issued for compensation | 
 
 | 
92,070
 | 
 
 | 
 
 | 
92,070
 | 
| Shares issued for services, shares | 
1,950,000
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Shares issued for services, amount | 
$ 195
 | 
59,459
 | 
 
 | 
 
 | 
59,654
 | 
| Stock options granted | 
 
 | 
96,964
 | 
 
 | 
 
 | 
96,964
 | 
| Foreign currency translation adjustment | 
 
 | 
 
 | 
 
 | 
(6,058)
 | 
(6,058)
 | 
| Net loss | 
 
 | 
 
 | 
(1,036,574)
 | 
 
 | 
(1,036,574)
 | 
| Ending balance, shares at Oct. 31, 2018 | 
1,081,449,960
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance, amount at Oct. 31, 2018 | 
$ 108,145
 | 
$ 103,524,179
 | 
$ (98,216,080)
 | 
$ (12,040)
 | 
$ 5,404,204
 |