| Significant Accounting Policies (Details) (USD $) | 3 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
| Jul. 31, 2013 | Apr. 30, 2013 | Jul. 31, 2013
 Stock Options [Member] | Jul. 31, 2012
 Stock Options [Member] | Jul. 31, 2013
 Warrant [Member] | Jul. 31, 2012
 Warrant [Member] | Jul. 31, 2013
 Convertible Debt [Member] | Jul. 31, 2012
 Convertible Debt [Member] | |
| Significant Accounting Policies [Abstract] | ||||||||
| Restricted cash | $ 265,310 | $ 265,173 | ||||||
| Letter of credit interest rate | 0.20% | |||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||||
| Antidilutive securities | 9,110,592 | 2,070,000 | 9,090,292 | 882,500 | 1,357,143 | 951,126 | ||
| Convertible debt | $ 800,000 | $ 650,000 | ||||||
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- Definition Interest rate related to letter of credit earned during period. No definition available. 
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- Details 
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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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- Definition Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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