|
Revenue by geographic location (Details) (USD $)
|
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Jan. 31, 2013
|
Jan. 31, 2012
|
Jan. 31, 2013
|
Jan. 31, 2012
|
|
| Revenues by geographic location | $ 6,438,961 | $ 8,420,135 | $ 21,396,469 | $ 29,095,949 |
|
United States
|
||||
| Revenues by geographic location | 4,572,914 | 6,091,393 | 16,553,265 | 23,357,207 |
|
Europe
|
||||
| Revenues by geographic location | 1,217,323 | 1,463,481 | 3,167,483 | 3,886,481 |
|
Other (principally Asia Pacific Region)
|
||||
| Revenues by geographic location | $ 648,724 | $ 865,261 | $ 1,675,721 | $ 1,852,261 |