Note 4 - Inventory (Details) (USD $)	Jul. 31, 2013	Apr. 30, 2013
Inventory Disclosure [Abstract]
Inventory Valuation Reserves	$ 677,000	$ 682,000

Amount of valuation reserve for inventory.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Name:	us-gaap_InventoryValuationReserves
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant