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Note 5 - Stockholders' Equity (Details) - Options Outstanding and Exercisable, by Exercise Range (USD $)
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9 Months Ended |
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Jan. 31, 2014
|
Apr. 30, 2013
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| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
|
| Options Outstanding, Weighted-Average Remaining Contractual Life (in Shares) |
260,967 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life |
6 years 270 days |
|
| Options Outstanding, Weighted-Average Exercise Price |
$ 4.92 |
$ 4.28 |
| Options Exercisable (in Shares) |
141,634 |
|
| Options Exercisable, Weighted- Average Exercise Price |
$ 4.28 |
|
|
$3.01 - $4.00 [Member]
|
|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
|
| Range of Exercise Prices |
$ 3.01 |
|
| Range of Exercise Prices |
$ 4.00 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life (in Shares) |
104,250 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life |
4 years 215 days |
|
| Options Outstanding, Weighted-Average Exercise Price |
$ 3.54 |
|
| Options Exercisable (in Shares) |
88,250 |
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| Options Exercisable, Weighted- Average Exercise Price |
$ 3.63 |
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|
$4.01 - $5.00 [Member]
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|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
|
| Range of Exercise Prices |
$ 4.01 |
|
| Range of Exercise Prices |
$ 5.00 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life (in Shares) |
23,967 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life |
8 years 109 days |
|
| Options Outstanding, Weighted-Average Exercise Price |
$ 4.35 |
|
| Options Exercisable (in Shares) |
7,300 |
|
| Options Exercisable, Weighted- Average Exercise Price |
$ 4.35 |
|
|
$5.01 - $6.00 [Member]
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|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
|
| Range of Exercise Prices |
$ 5.01 |
|
| Range of Exercise Prices |
$ 6.00 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life (in Shares) |
115,000 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life |
8 years 80 days |
|
| Options Outstanding, Weighted-Average Exercise Price |
$ 5.54 |
|
| Options Exercisable (in Shares) |
38,334 |
|
| Options Exercisable, Weighted- Average Exercise Price |
$ 5.21 |
|
|
$7.01 - $8.00 [Member]
|
|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
|
| Range of Exercise Prices |
$ 7.01 |
|
| Range of Exercise Prices |
$ 8.00 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life (in Shares) |
7,750 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life |
4 years 222 days |
|
| Options Outstanding, Weighted-Average Exercise Price |
$ 7.05 |
|
| Options Exercisable (in Shares) |
7,750 |
|
| Options Exercisable, Weighted- Average Exercise Price |
$ 7.05 |
|
|
$10.01 - $11.00 [Member]
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|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
|
|
| Range of Exercise Prices |
$ 10.01 |
|
| Range of Exercise Prices |
$ 11.00 |
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| Options Outstanding, Weighted-Average Remaining Contractual Life (in Shares) |
10,000 |
|
| Options Outstanding, Weighted-Average Remaining Contractual Life |
9 years 313 days |
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| Options Outstanding, Weighted-Average Exercise Price |
$ 11.83 |
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