Note 7 - Warrants

6 Months Ended

Jun. 30, 2019

Notes to Financial Statements

Warrants [Text Block]

7. Warrants

At

June 30, 2019

and

December 31, 2018,

we had

4,048,505

and

4,080,005

warrants outstanding, respectively and exercisable with a weighted average exercise price of

$4.34

and

$4.35,

respectively. During the

three

and

six

month period ended

June 30, 2019,

24,000

and

29,000

warrants were exercised with a weighted average exercise price of

$4.75

,

yielding proceeds of

$114,000

and

$138,000,

respectively. The outstanding warrants have expiration dates between

March 2021

and

May 2021.