Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Cash flows from operating activities:
Net loss	$ (5,653)	$ (6,785)	$ (6,647)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	999	1,016	997
Provision (recovery of) for doubtful accounts	53	(13)	(30)
Loss on disposal of asset	0	2	0
Amortization of debt issuance costs	148	177	31
Depreciation and amortization	271	203	135
Changes in operating assets and liabilities:
Accounts receivable	(3,507)	887	1,774
Inventories	430	70	(1,008)
Prepaid expenses and other	(707)	9	34
Accounts payable	1,686	564	(850)
Accrued expenses	53	539	(371)
Customer deposits and deferred revenue	1,730	(2,909)	3,702
Income taxes payable	2	(41)	(15)
Deferred rent	0	0	(8)
Net cash used in operating activities	(4,495)	(6,281)	(2,256)
Cash flows from investing activities:
Purchases of property and equipment	(477)	(919)	(118)
Net cash used in investing activities	(477)	(919)	(118)
Cash flows from financing activities:
Line of credit borrowings (repayments), net	0	2,000	(777)
Proceed from issuance of convertible notes, net	0	(6)	3,760
Proceeds from issuance of common stock under public offering, net of issuance costs	15,832	0	0
Proceeds from issuance of common stock under private placement, net of issuance costs	5,299	0	2,574
Proceeds from issuance of common stock under employee plans	704	512	855
Net cash provided by financing activities	21,835	2,506	6,412
Effect of exchange rates on cash and cash equivalents	1	106	(320)
Net increase (decrease) in cash and cash equivalents	16,864	(4,588)	3,718
Cash and cash equivalents, beginning of year	939	5,527	1,809
Cash and cash equivalents, end of year	17,803	939	5,527
Supplemental Cash Flow Information:
Cash paid during the year for Income taxes	18	47	26
Cash paid during the year for Interest	516	302	130
Non-cash transactions:
Net change in capitalized stock-based compensation	0	(20)	(4)
Line of credit converted to convertible notes	0	2,000	0
Fair value of common stock issued to settle accounts payable	$ 323	$ 0	$ 0