UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
Operating activities:
Net loss	$ (2,913)	$ (3,548)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	775	808
Depreciation expense	37	56
Change in fair value of warrant liability	0	(155)
Changes in operating assets and liabilities:
Accounts receivable	(398)	400
Prepaid expenses and other current assets	(20)	(73)
Restricted cash	13	0
Accounts payable	22	347
Accrued liabilities	43	(196)
Deferred revenue	(102)	(427)
Net cash used in operating activities	(2,543)	(2,788)
Investing activities:
Purchase of property and equipment	(29)	(33)
Net cash used in investing activities	(29)	(33)
Financing activities:
Payment of issuance costs related to 2015 Private Placement	(18)	0
Capital lease payments	(7)	0
Net cash used in financing activities	(25)	0
Exchange rate effect on cash and cash equivalents	0	(18)
Decrease in cash and cash equivalents	(2,597)	(2,839)
Cash and cash equivalents, beginning of period	9,357	9,561
Cash and cash equivalents, end of period	$ 6,760	$ 6,722