Accrued Liabilities - Accrued liabilities (Details) - USD ($)	Apr. 30, 2015	Apr. 30, 2014
Payables and Accruals [Abstract]
Payroll, including vacation	$ 27,000	$ 226,000
Commissions	$ 10,000	75,000
Bonuses		70,000
Lease legal settlement		225,000
Deferred gain on equipment sale	$ 72,000	72,000
Accounting and audit	53,000	85,000
Other	120,000	176,000
Total accrued liabilities	$ 282,000	$ 929,000