Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2016
Cash flows from operating activities:
Net income (loss)	$ 528	$ (5,653)	$ (6,785)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Stock-based compensation expense	996	999	1,016
(Recovery of) provision for doubtful accounts	(58)	53	(13)
Loss on disposal of asset	0	0	2
Amortization of debt issuance costs	0	148	177
Depreciation and amortization	417	271	203
Changes in operating assets and liabilities:
Accounts receivable	1,260	(3,507)	887
Inventories	(2,073)	430	70
Prepaid expenses and other	59	(707)	9
Accounts payable	(1,095)	1,686	564
Accrued expenses	62	53	539
Customer deposits and deferred revenue	(1,482)	1,730	(2,909)
Deferred rent	63	0	0
Income taxes payable	(28)	2	(41)
Net cash used in operating activities	(1,351)	(4,495)	(6,281)
Cash flows from investing activities:
Purchases of property and equipment	(572)	(477)	(919)
Net cash used in investing activities	(572)	(477)	(919)
Cash flows from financing activities:
Line of credit borrowings (repayments), net	0	0	2,000
Proceed from issuance of convertible notes, net	0	0	(6)
Proceeds from issuance of common stock under public offering, net of issuance costs	0	15,832	0
Proceeds from issuance of common stock under private placement, net of issuance costs	0	5,299	0
Proceeds from issuance of common stock under employee plans	925	704	512
Net cash provided by financing activities	925	21,835	2,506
Effect of exchange rates on cash and cash equivalents	43	1	106
Net (decrease) increase in cash and cash equivalents	(955)	16,864	(4,588)
Cash and cash equivalents, beginning of year	17,803	939	5,527
Cash and cash equivalents, end of year	16,848	17,803	939
Supplemental Cash Flow Information:
Cash paid during the year for Income taxes	37	18	47
Cash paid during the year for Interest	550	516	302
Supplemental disclosure of non-cash flow information:
Net change in capitalized stock-based compensation	0	0	(20)
Line of credit converted to convertible notes	0	0	2,000
Fair value of common stock issued to settle accounts payable	$ 0	$ 323	$ 0