Customer Deposits (Details) (USD $)			6 Months Ended
	Oct. 31, 2012	Apr. 30, 2012	Oct. 31, 2012 Customer Advances [Member]	Oct. 31, 2012 Customer Deposits [Member]
Customer Advances and Deposits [Line Items]
Customer Advances Not Received			$ 1,400,000
Customer Advances Received			674,000
Customer Advances, Current			22,000
Customer deposits	$ 731,000	$ 206,000		$ 35,000