Summary of Significant Accounting Policies - Reconciliation of the numerator and denominator used in computing basic and diluted net loss per share (Details) (USD $)	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Summary Of Significant Accounting Policies - Reconciliation Of Numerator And Denominator Used In Computing Basic And Diluted Net Loss Per Share Details
Loss (numerator)	$ (1,247,757)	$ (1,178,874)	$ (2,223,474)	$ (2,032,831)
Shares (denominator)	10,703,309	10,703,309	10,703,309	10,548,961
Net loss per share, basic	$ (0.12)	$ (0.11)	$ (0.21)	$ (0.19)
Effect of dilutive securities – stock options
Effect of dilutive securities – warrants
Loss (numerator)	$ (1,247,757)	$ (1,178,874)	$ (2,223,474)	$ (2,032,831)
Shares (denominator)	10,703,309	10,703,309	10,703,309	10,548,961
Net loss per share, diluted	$ (0.12)	$ (0.11)	$ (0.21)	$ (0.19)