Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Schedule of Warrants) (Details)

v3.7.0.1
Stockholders' Equity (Schedule of Warrants) (Details) - Warrant [Member]
 12 Months Ended
Apr. 30, 2017
USD ($)
$ / shares
shares
Number of Shares  
Balance Outstanding, April 30, 2016 | shares 2,001,356
Granted | shares 62,500
Exercised | shares (8,834)
Forfeited | shares (1,120,968)
Expired | shares (21,256)
Balance Outstanding, April 30, 2017 | shares 912,798
Exercisable, April 30, 2017 | shares 912,798
Weighted Average Exercise Price  
Balance Outstanding, April 30, 2016 | $ / shares $ 2.31
Granted | $ / shares 2.40
Exercised | $ / shares 3.99
Forfeited | $ / shares 1.86
Expired | $ / shares 3.99
Balance Outstanding, April 30, 2017 | $ / shares 2.82
Exercisable, April 30, 2017 | $ / shares $ 2.82
Weighted Average Remaining Contractual Term  
Balance Outstanding, April 30, 2017 1 year 7 months 6 days
Exercisable, April 30, 2017 1 year 7 months 6 days
Aggregate Intrinsic Value  
Balance Outstanding, April 30, 2016 | $ $ 1,022,078
Granted | $ 78,125
Balance Outstanding, April 30, 2017 | $ 1,100,203
Exercisable, April 30, 2017 | $ $ 1,100,203