BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 1,725,806	$ 1,698,506
Statement
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common Stock, authorized shares	100,000,000us-gaap_CommonStockSharesAuthorized	100,000,000us-gaap_CommonStockSharesAuthorized
Common Stock, outstanding shares	27,613,397us-gaap_CommonStockSharesOutstanding	27,187,702us-gaap_CommonStockSharesOutstanding
Common stock in treasury - at cost; outstanding	722,920us-gaap_TreasuryStockShares	722,920us-gaap_TreasuryStockShares
Class B
Statement
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, authorized shares	5,000,000	5,000,000
Series I, Class B
Statement
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, outstanding shares	98,500	103,500
Preferred Stock, liquidation preference (in dollars)	615,625	646,875
Series II, Class B
Statement
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, outstanding shares	176,200	178,700
Preferred Stock, liquidation preference (in dollars)	2,202,500	2,233,750
Series III, Class B
Statement
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, outstanding shares	130,245	130,245
Preferred Stock, liquidation preference (in dollars)	1,628,063	1,628,063
Series IV, Class B
Statement
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, outstanding shares	542,500	542,500
Preferred Stock, liquidation preference (in dollars)	5,967,500	5,967,500
Series V, Class B
Statement
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred Stock, outstanding shares	40,000	40,000
Preferred Stock, liquidation preference (in dollars)	$ 176,000	$ 176,000

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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