Quarterly report pursuant to sections 13 or 15(d)

Stock-Based Compensation (Details)

v2.4.0.6
Stock-Based Compensation (Details) (USD $)
3 Months Ended 1 Months Ended 3 Months Ended 1 Months Ended 3 Months Ended
Oct. 31, 2012
Oct. 31, 2011
Oct. 31, 2012
Maximum
Oct. 31, 2011
Maximum
Oct. 31, 2012
Minimum
Oct. 31, 2011
Minimum
Oct. 31, 2012
Research and development expense
Oct. 31, 2011
Research and development expense
Oct. 31, 2012
General and administrative expense
Oct. 31, 2011
General and administrative expense
Oct. 31, 2012
Employees
Oct. 31, 2011
Employees
Oct. 31, 2012
Employees
Maximum
Oct. 31, 2012
Employees
Minimum
Oct. 31, 2011
Director
Oct. 31, 2012
Consultant
May 31, 2011
2011 Plan
May 31, 2011
2011 Plan
Maximum
Oct. 31, 2012
2011 Plan
Maximum
May 31, 2011
2011 Plan
Minimum
Oct. 31, 2012
2011 Plan
Minimum
Stock-based compensation                                          
Number of shares authorized                                 5,200,000        
Purchase price of incentive stock options as a percentage of its fair value                                       100.00% 100.00%
Term of stock options                     10 years 10 years     10 years 3 years   10 years 10 years    
Provisional percentage of outstanding stock owned by stockholders                                       10.00% 10.00%
Exercise price as a percentage of fair value of common stock for stockholders who own more than 10% of outstanding stock                                       110.00% 110.00%
Options granted to purchase shares 1,355,000                   155,000 355,000     100,000 1,200,000          
Vesting period                       2 years 3 years 2 years 1 year            
Exercise price, high end of the range (in dollars per share)                     $ 0.42                    
Exercise price, low end of the range (in dollars per share)                     $ 0.20                    
Exercise price (in dollars per share)                       $ 0.40     $ 0.40 $ 0.18          
Expected volatility, minimum (as a percent) 79.25%                                        
Expected volatility, maximum (as a percent) 97.85%                                        
Expected volatility (as a percent)   85.96%                                      
Risk-free interest rate (as a percent)   0.96% 1.92%   0.36%                                
Expected forfeiture rate (as a percent) 0.00% 0.00%                                      
Expected term     10 years 6 years 3 years 5 years                              
Stock-based compensation expense recognized $ 180,000 $ 5,100         $ 20,000 $ 2,500 $ 160,000 $ 2,600                      
Option Shares Outstanding                                          
Balance at the beginning of the period (in shares) 3,175,000                                        
Granted (in shares) 1,355,000                   155,000 355,000     100,000 1,200,000          
Forfeited/Cancelled (in shares) (20,200)                                        
Balance at the end of the period (in shares) 4,509,800                                        
Weighted-Average Exercise Price                                          
Balance at the beginning of the period (in dollars per share) $ 0.24                                        
Granted (in dollars per share) $ 0.18                                        
Exercised (in dollars per share) $ 0.00                                        
Forfeited/Cancelled (in dollars per share) $ 0.32                                        
Balance at the end of the period (in dollars per share) $ 0.22                                        
Aggregate Intrinsic Value                                          
Balance at the beginning of the period (in dollars) 24,000                                        
Granted (in dollars) 171,000                                        
Forfeited/Cancelled (in dollars) 1,000                                        
Balance at the end of the period (in dollars) $ 437,000