C. REVENUE (Details - Contract assets and liabilities) - USD ($) |
Mar. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Revenue from Contract with Customer [Abstract] | ||
| Contract assets | $ 15,469 | $ 104,989 |
| Contract liabilities | 1,160,947 | 1,052,367 |
| Net contract liabilities | $ 1,145,478 | $ 947,378 |
| X | ||||||||||
- Definition Contract liabilities over contract assets No definition available.
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| X | ||||||||||
- Definition Amount, before allowance for credit loss, of right to consideration in exchange for good or service transferred to customer, when right is conditioned on something other than passage of time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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