UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Operating activities:
Net loss	$ (4,556)	$ (3,297)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,028	1,364
Depreciation expense	102	103
Change in fair value of warrant liability	2,048	(233)
Changes in operating assets and liabilities:
Accounts receivable	(962)	(43)
Prepaid expenses, deposits and other	96	110
Restricted cash	(1)	0
Accounts payable	(220)	(467)
Accrued liabilities	(282)	(111)
Deferred revenue	845	20
Net cash used in operating activities	(1,902)	(2,554)
Investing activities:
Purchase of property and equipment	(76)	(28)
Net cash provided by investing activities	(76)	(28)
Financing activities:
Proceeds from exercise of stock options	9	0
Net cash used in financing activities	9	0
Exchange rate effect on cash and cash equivalents	(20)	27
Decrease in cash and cash equivalents	(1,989)	(2,555)
Cash and cash equivalents, beginning of period	9,561	4,716
Cash and cash equivalents, end of period	$ 7,572	$ 2,161