Consolidated Statements of Cash Flows - USD ($)
12 Months Ended
May 31, 2018
May 31, 2017
May 31, 2016
Cash flows relating to operating activities      
Net income (loss) $ 210,639 $ (1,073,364) $ (1,515,189)
Adjustments to reconcile net income (loss) to net cash used in operating activities:      
Depreciation and amortization 205,239 219,082 245,824
(Gain) loss on disposal of property and equipment 619 (7,223) (299)
Stock based compensation 50,336 79,765 58,198
(Increase) decrease in:      
Accounts receivable 311,433 (272,506) 548,650
Inventories (1,494,009) 478,532 (192,509)
Prepaid expenses (32,463) 14,267 20,737
Income taxes receivable 7,310 1,122 (7,403)
Increase (decrease) in:      
Accounts payable (78,049) 230,242 46,787
Accrued liabilities and customer deposits (187,897) 181,795 (24,604)
Income taxes payable 3,993 0 0
Net cash used in operating activities (1,002,849) (148,288) (819,808)
Cash flows relating to investing activities      
Purchase of property and equipment (8,467) (52,633) (3,520)
Proceeds from sale of property and equipment 1,500 52,535 14,950
Net cash provided by (used in) investing activities (6,967) (98) 11,430
Cash flows relating to financing activities      
Common stock issued through rights offering, net of expenses 2,386,029 0 0
Net cash provided by financing activities 2,386,029 0 0
Effect of foreign exchange translation on cash (132,287) 27,307 1,410
Increase (decrease) in cash and cash equivalents 1,243,926 (121,079) (806,968)
Cash, cash equivalents and restricted cash, beginning of period 867,607 988,686 1,795,654
Cash, cash equivalents and restricted cash, end of period 2,111,533 867,607 988,686
Supplemental disclosure of cash flow information      
Cash paid during the year for income taxes 14,661 27,772 27,496
Cash paid during the year for interest $ 1,401 $ 2,982 $ 2,988