Note I - Stock Option Plan Comparison (Details)	6 Months Ended
	Oct. 31, 2015 shares
The 1997 Plan [Member]
Minimum exercise price as a percentage of fair market value at date of grant	100.00%
Last expiration date for outstanding options	Jul. 02, 2017
Shares available for grant at October 31, 2015 (in shares)	0
Restated Option Plan [Member]
Minimum exercise price as a percentage of fair market value at date of grant	100.00%
Last expiration date for outstanding options	Aug. 05, 2025
Shares available for grant at October 31, 2015 (in shares)	322,250