Annual report pursuant to Section 13 and 15(d)

6. STOCK OPTIONS AND WARRANTS (Details - Options by exercise price)

v3.21.2
6. STOCK OPTIONS AND WARRANTS (Details - Options by exercise price) - $ / shares
12 Months Ended
Apr. 30, 2021
Apr. 30, 2020
Apr. 30, 2019
Options [Member]      
Number of Options 41,333 44,800 71,634
Weighted Average Remaining Contractual LIfe (years) 1 year 6 months 29 days    
Weighted Average Exercisable Price $ 79.97 $ 94.36 $ 160.91
Numer of Options Exercisable 37,333    
$156.00 [Member]      
Number of Options 6,967    
Weighted Average Remaining Contractual LIfe (years) 6 months 18 days    
Weighted Average Exercisable Price $ 6,967    
Numer of Options Exercisable 156    
$87.00 [Member]      
Number of Options 1,634    
Weighted Average Remaining Contractual LIfe (years) 10 months 17 days    
Weighted Average Exercisable Price $ 1,634    
Numer of Options Exercisable 87    
$110.10 [Member]      
Number of Options 800    
Weighted Average Remaining Contractual LIfe (years) 1 year    
Weighted Average Exercisable Price $ 800    
Numer of Options Exercisable 110.1    
$109.35 [Member]      
Number of Options 1,200    
Weighted Average Remaining Contractual LIfe (years) 1 year 2 months 8 days    
Weighted Average Exercisable Price $ 1,200    
Numer of Options Exercisable 109.35    
$133.50 [Member]      
Number of Options 800    
Weighted Average Remaining Contractual LIfe (years) 1 year 2 months 19 days    
Weighted Average Exercisable Price $ 800    
Numer of Options Exercisable 133.5    
$82.95 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 8 months 19 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 82.95    
$83.70 [Member]      
Number of Options 6,000    
Weighted Average Remaining Contractual LIfe (years) 1 year    
Weighted Average Exercisable Price $ 6,000    
Numer of Options Exercisable 83.7    
$80.10 [Member]      
Number of Options 800    
Weighted Average Remaining Contractual LIfe (years) 2 years 4 months 6 days    
Weighted Average Exercisable Price $ 800    
Numer of Options Exercisable 80.1    
$80.85 [Member]      
Number of Options 667    
Weighted Average Remaining Contractual LIfe (years) 1 year    
Weighted Average Exercisable Price $ 667    
Numer of Options Exercisable 80.85    
$102.45 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 1 year 29 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 102.45    
$97.35 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 1 year 2 months 19 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 97.35    
$74.25 [Member]      
Number of Options 6,000    
Weighted Average Remaining Contractual LIfe (years) 1 year 8 months 23 days    
Weighted Average Exercisable Price $ 6,000    
Numer of Options Exercisable 74.25    
$57.00 [Member]      
Number of Options 800    
Weighted Average Remaining Contractual LIfe (years) 3 years 4 months 24 days    
Weighted Average Exercisable Price $ 800    
Numer of Options Exercisable 57    
$60.60 [Member]      
Number of Options 667    
Weighted Average Remaining Contractual LIfe (years) 1 year 6 months    
Weighted Average Exercisable Price $ 667    
Numer of Options Exercisable 60.6    
$55.5 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 1 year 7 months 2 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 55.5    
$51.00 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 1 year 8 months 19 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 51    
$61.20 [Member]      
Number of Options 6,000    
Weighted Average Remaining Contractual LIfe (years) 2 years 2 months 16 days    
Weighted Average Exercisable Price $ 6,000    
Numer of Options Exercisable 61.2    
$36.00 [Member]      
Number of Options 667    
Weighted Average Remaining Contractual LIfe (years) 2 years    
Weighted Average Exercisable Price $ 667    
Numer of Options Exercisable 36    
$37.05 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 2 years 1 month 2 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 37.05    
$15.75 [Member]      
Number of Options 6,000    
Weighted Average Remaining Contractual LIfe (years) 2 years 2 months 19 days    
Weighted Average Exercisable Price $ 2,000    
Numer of Options Exercisable 10.05    
$10.05 [Member]      
Number of Options 333    
Weighted Average Remaining Contractual LIfe (years) 2 years 9 months 18 days    
Weighted Average Exercisable Price $ 333    
Numer of Options Exercisable 15.7