Stockholders' Equity (Summary Of Details Of Outstanding Warrants) (Details)	12 Months Ended
	Apr. 30, 2013
$2.25 - $2.55 [Member]
Date of issuance	June 29, 2010
Number of warrants issued	718,860
Number of warrants outstanding	718,860
Exercise price	2.45
Expiration date	June 29, 2020
$2.65 - $2.86 [Member]
Date of issuance	April 24, 2009
Number of warrants issued	190,182
Number of warrants outstanding	190,182
Exercise price	2.75
Expiration date	April 24, 2014