Disclosure - Summary of Significant Accounting Policies - Accounts receivable (Details) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Notes to Financial Statements
Trade receivables	$ 2,962,000	$ 2,621,000
VAT receivable	123,000	184,000
Allowance for doubtful accounts and sales returns	200,000	200,000
Accounts receivable	$ 2,885,000	$ 2,605,000