| D. ACCOUNTS RECEIVABLE (Details) - USD ($) | Sep. 30, 2019 | Dec. 31, 2018 | 
|---|---|---|
| Components of accounts receivable | ||
| Accounts receivable | $ 2,102,246 | $ 1,146,832 | 
| Allowance for doubtful accounts | (22,248) | (65,541) | 
| Accounts receivable, net | $ 2,079,998 | $ 1,081,291 | 
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- Definition Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- References No definition available. 
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- Definition Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of allowance for credit loss on accounts receivable, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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