Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (5,235)	$ 528	$ (5,653)
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Stock-based compensation expense	905	996	999
(Recovery of) provision for doubtful accounts	(3)	(58)	53
Amortization of debt issuance costs	0	0	148
Depreciation and amortization	431	417	271
Changes in operating assets and liabilities:
Accounts receivable	(2,043)	1,260	(3,507)
Inventories	(112)	(2,073)	430
Prepaid expenses and other	84	59	(707)
Accounts payable	210	(1,095)	1,686
Accrued expenses	402	62	53
Customer deposits and deferred revenue	(355)	(1,482)	1,730
Deferred rent	90	63	0
Income taxes payable	(11)	(28)	2
Net cash used in operating activities	(5,637)	(1,351)	(4,495)
Cash flows from investing activities:
Purchases of property and equipment	(173)	(572)	(477)
Net cash used in investing activities	(173)	(572)	(477)
Cash flows from financing activities:
Repayment of Convertible Notes	(6,110)	0	0
Proceeds from issuance of common stock under public offering, net of issuance costs	0	0	15,832
Proceeds from issuance of common stock under private placement, net of issuance costs	0	0	5,299
Proceeds from issuance of common stock under employee plans	559	925	704
Net cash (used in) provided by financing activities	(5,551)	925	21,835
Effect of exchange rates on cash and cash equivalents	(59)	43	1
Net (decrease) increase in cash and cash equivalents	(11,420)	(955)	16,864
Cash and cash equivalents, beginning of year	16,848	17,803	939
Cash and cash equivalents, end of year	5,428	16,848	17,803
Supplemental Cash Flow Information:
Cash paid during the year for Income taxes	37	37	18
Cash paid during the year for Interest	610	550	516
Supplemental disclosure of non-cash flow information:
Fair value of common stock issued to settle accounts payable	0	0	323
Net transfer of equipment between inventory and property and equipment	$ 119	$ 0	$ 0