Income Taxes (Schedule of Defered Income Tax Assets and Liabilities) (Details) - USD ($)	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Deferred tax assets:
Net operating loss	$ 8,626,748	$ 8,271,894
Allowance for doubtful accounts (recovery)	(20,029)	26,793
Intangible assets	201,942	249,099
Deferred rent	16,911	11,678
Stock-based compensation	820,257	694,900
Contributions carryforward	93	93
Total deferred tax assets	9,645,922	9,254,457
Deferred tax liabilities:
Property and equipment	(174,260)	(185,683)
Total deferred tax liabilities	(174,260)	(185,683)
Deferred tax assets, net	9,471,662	9,068,774
Valuation allowance:
Valuation allowance	(9,471,662)	(9,068,774)	$ (8,240,200)
Net deferred tax asset