C. REVENUE (Details - Contract assets and liabilities) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
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| Revenue from Contract with Customer [Abstract] | ||
| Contract assets | $ 104,989 | $ 188,120 |
| Contract liabilities | 1,052,367 | 764,184 |
| Net contract liabilities | 947,378 | 576,064 |
| Decrease in contract assets | (83,131) | (126,629) |
| Increase in contract liabilities | 288,183 | $ (468,439) |
| Total variance in contract assets and liabilties | $ 371,314 | |
| X | ||||||||||
- Definition Contract liabilities over contract assets No definition available.
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| X | ||||||||||
- Definition Total variance in contract assets and liabilties 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/2009/role/commonPracticeRef
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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 | ||||||||||
- Definition Amount of increase (decrease) in 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/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- References No definition available.
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