Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Nov. 30, 2015	Nov. 30, 2014
Cash Flows from Operating Activities:
Net income (loss)	$ 165,547	$ (305,379)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	674,993	686,666
Decrease (Increase) in deferred tax asset	28,650	(215,683)
Stock based compensation	26,712	26,712
Changes in trade accounts receivable	425,164	1,306,873
Changes in related party receivable	(17,274)	(134,027)
Changes in inventory	(880,085)	132,862
Changes in prepaid expenses	(94,643)	3,174
Changes in accounts payable and accrued expenses	1,272,247	$ 305,236
Other	(250)
Net cash provided by operating activities	1,601,061	$ 1,806,434
Cash Flows from Investing Activities:
Purchase of property and equipment	(540,374)	(510,310)
Cash Flows from Financing Activities:
Proceeds from revolving loan	650,000	100,000
Payments on long-term debt and capitalized lease	(983,244)	(955,535)
Payments on revolving loan	(300,000)	(385,000)
Proceeds from exercised stock options	57,000	84,000
Dividends paid on preferred stock	(162,945)	(136,233)
Dividends paid by variable interest entity	(102,000)	(102,000)
Net cash used in financing activities	(841,189)	(1,394,768)
Net Increase (Decrease) in Cash	219,498	(98,644)
Cash, beginning of period	598,887	661,263
Cash, end of period	$ 818,385	562,619
Non-Cash Activities:
Acquisition of equipment from related party		75,000
Preferred dividend accrual		26,712
Supplemental Information:
Interest paid	$ 236,755	$ 260,993