|
Note 5 - Stockholders' Equity (Tables)
|
9 Months Ended |
|
Jan. 31, 2014
|
| Note 5 - Stockholders' Equity (Tables) [Line Items] |
|
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
|
|
|
Nine Months
Ended
January 31, 2014
|
|
Nine Months
Ended
January 31, 2013
|
|
Risk-free interest rate
|
|
|
2.97%
|
|
|
|
2.97%
|
|
|
Expected life, in years
|
|
|
6
|
|
|
|
6
|
|
|
Expected volatility
|
|
82.59
|
–
|
83.23%
|
|
65.52
|
–
|
80.48%
|
|
Dividend yield
|
|
|
0.0%
|
|
|
|
0.0%
|
|
|
Forfeiture rate
|
|
|
11.40%
|
|
|
|
9.20%
|
|
|
| Schedule of Share-based Compensation, Activity [Table Text Block] |
|
Stock Options
|
|
Number
of
Shares
|
|
|
Weighted-Average
Exercise Price
|
|
|
Weighted-Average
Remaining
Contract Life (Years)
|
|
|
Outstanding options at April 30, 2013
|
|
|
205,500
|
|
|
$
|
4.28
|
|
|
6.54
|
|
|
Granted
|
|
|
70,000
|
|
|
$
|
6.71
|
|
|
9.58
|
|
|
Exercised
|
|
|
13,533
|
|
|
$
|
4.62
|
|
|
|
-
|
|
|
Forfeited
|
|
|
1,000
|
|
|
$
|
3.88
|
|
|
|
-
|
|
|
Outstanding options at January 31, 2014
|
|
|
260,967
|
|
|
$
|
4.92
|
|
|
6.74
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Outstanding exercisable at January 31, 2014
|
|
|
141,634
|
|
|
$
|
4.28
|
|
|
4.93
|
|
|
| Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] |
|
|
|
|
|
Options Outstanding
|
|
|
Options Exercisable
|
|
|
Range of Exercise
Prices
|
|
|
|
Number
Outstanding at
January 31, 2014
|
|
Weighted-
Average
Remaining
Contractual
Life
(Years)
|
|
Weighted-
Average
Exercise
Price
|
|
|
Number
Exercisable
at
January 31, 2014
|
|
|
Weighted-
Average
Exercise
Price
|
|
|
$3.01
|
-
|
$4.00
|
|
|
|
104,250
|
|
4.59
|
|
$
|
3.54
|
|
|
|
88,250
|
|
|
$
|
3.63
|
|
|
$4.01
|
-
|
$5.00
|
|
|
|
23,967
|
|
8.30
|
|
$
|
4.35
|
|
|
|
7,300
|
|
|
$
|
4.35
|
|
|
$5.01
|
-
|
$6.00
|
|
|
|
115,000
|
|
8.22
|
|
$
|
5.54
|
|
|
|
38,334
|
|
|
$
|
5.21
|
|
|
$7.01
|
-
|
$8.00
|
|
|
|
7,750
|
|
4.61
|
|
$
|
7.05
|
|
|
|
7,750
|
|
|
$
|
7.05
|
|
|
$10.01
|
-
|
$11.00
|
|
|
|
10,000
|
|
9.86
|
|
$
|
11.83
|
|
|
|
-
|
|
|
|
-
|
|
|
Total
|
|
|
|
|
260,967
|
|
6.74
|
|
$
|
4.92
|
|
|
|
141,634
|
|
|
$
|
4.28
|
|
|
|
Restricted Stock [Member]
|
|
| Note 5 - Stockholders' Equity (Tables) [Line Items] |
|
| Schedule of Share-based Compensation, Activity [Table Text Block] |
|
Restricted Stock
|
|
Number
of
Shares
|
|
|
Outstanding awards at April 30, 2013
|
|
|
11,007
|
|
|
Granted
|
|
|
4,608
|
|
|
Issued
|
|
|
4,469
|
|
|
Forfeited
|
|
|
-
|
|
|
Outstanding awards at January 31, 2014
|
|
|
11,146
|
|
|
|
|
|
|
|
|
Outstanding vested at January 31, 2014
|
|
|
-
|
|
|