Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 27,008	$ 48,396
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	527,816	388,324
Deferred income taxes	(18,850)	(5,285)
Stock-based compensation		13,356
Changes in trade receivables	937,275	(349,570)
Changes in related party receivable	14,492	33,076
Changes in inventory	(14,003)	(624,923)
Changes in prepaid expenses and other	51,935	10,249
Change in other assets	200	(1,303)
Changes in accounts payable and accrued expenses	(237,270)	1,817,402
Net cash provided by operating activities	1,288,603	1,329,722
Cash Flows from Investing Activities:
Purchase of property and equipment	(849,062)	(282,534)
Cash Flows from Financing Activities:
Payments on long-term debt and capitalized leases	(570,014)	(495,855)
Payments on revolving loan		(300,000)
Proceeds from exercised stock options	57,000
Payments of preferred dividends	(87,746)	(81,027)
Distributions by variable interest entity	(51,000)	(51,000)
Net cash used in financing activities	(651,760)	(927,882)
Net Increase (Decrease) in Cash	(212,219)	119,306
Cash, beginning of period	897,377	598,887
Cash, end of period	685,158	718,193
Non-Cash Activities:
Acquisition of equipment by capital lease	2,731,152
Conversion of accrued interest to long-term debt	2,475,690
Preferred dividend accrual	57,329	55,206
Supplemental Information:
Interest paid	$ 191,333	$ 126,646