CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	6 Months Ended
	Nov. 30, 2015	Nov. 30, 2014
Cash flows from operating activities:
Net loss	$ (139,103)	$ (457,296)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	116,396	126,176
Stock option expense	2,562	1,804
Change in provision for allowance for doubtful accounts	(8,653)	(16,659)
Inventory reserve	$ 4,216	7,423
Gain on disposal of equipment		(665)
Decrease in deferred rent liability	$ (13,072)	$ (9,262)
Increase in deferred tax assets	(129,000)
Changes in assets and liabilities:
Accounts receivable	(52,362)	$ 900,454
Inventories	(214,238)	(231,601)
Prepaid expenses and other assets	49,986	(56,787)
Accounts payable and other accrued expenses	(63,233)	(88,082)
Accrued compensation	21,459	8,491
Net cash (used in) provided by operating activities	(425,042)	183,996
Cash flows from investing activities:
Purchases of property and equipment	$ (28,294)	(8,654)
Proceeds from sales of equipment		1,900
Increase in intangibles	$ (925)	(14,136)
Net cash used in investing activities	(29,219)	(20,890)
Cash flows from financing activities:
Proceeds from exercise of stock options	10,298	3,495
Net cash provided financing activities	10,298	3,495
Effect of exchange rate changes in cash	(1,366)	(1,678)
Net (decrease) increase in cash and cash equivalents	(445,329)	164,923
Cash and cash equivalents at beginning of period	1,088,307	1,509,125
Cash and cash equivalents at end of period	642,978	1,674,048
Cash paid during the period for:
Interest	54	17
Income taxes	$ 0	$ 0