Customer Deposits (Details) (USD $)			3 Months Ended	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012 Customer Advances [Member]	Apr. 30, 2012 Customer Advances [Member]	Jul. 31, 2012 Customer Deposits [Member]
Customer Advances and Deposits [Line Items]
Customer Advances Not Received			$ 1,400,000
Customer Advances Received			432,000	1,337,000
Customer Advances, Current			22,000
Customer deposits	$ 471,000	$ 206,000			$ 17,000