Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)
Dec. 31, 2015
Mar. 31, 2015
 [1]
Allowance for uncollectible accounts $ 15,000 $ 15,000
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, shares authorized (in shares) 6,000,000 6,000,000
Common stock, shares issued (in shares) 4,844,845 4,857,953
Common stock, shares outstanding (in shares) 4,844,845 4,857,953
[1] The March 31, 2015 Balance Sheet is derived from the audited financial statements contained in our Annual Report on Form 10-K for the fiscal year ended March 31, 2015.