| 5. | Income Taxes |
| | | 2017 | | 2016 | | 2015 | | |||
| Current: | | | | | | | | | | |
| Federal | | $ | - | | $ | - | | $ | - | |
| State | | | 7,299 | | | 11,286 | | | 16,596 | |
| Total current | | | 7,299 | | | 11,286 | | | 16,596 | |
| | | | | | | | | | | |
| Deferred: | | | | | | | | | | |
| Federal | | | (625,953) | | | (100,174) | | | (552,167) | |
| State | | | (84,424) | | | (3,495) | | | (66,542) | |
| Valuation Allowance | | | 739,578 | | | 393,814 | | | 618,709 | |
| Total deferred | | | 29,201 | | | 290,145 | | | - | |
| | | $ | 36,500 | | $ | 301,431 | | $ | 16,596 | |
| | | 2017 | | 2016 | | 2015 | | |||
| | | | | | | | | | | |
| Computed tax at federal statutory rate | | $ | (697,736) | | $ | (681,156) | | $ | (598,643) | |
| State income taxes, net of federal tax (benefit) provision | | | (49,124) | | | (38,971) | | | (29,799) | |
| Non deductible expenses | | | 15,491 | | | 13,915 | | | 14,683 | |
| Federal research credit | | | (9,661) | | | (15,144) | | | (6,738) | |
| Book tax depreciation adjustment | | | - | | | 517,736 | | | - | |
| Expiring State NOLs | | | 39,697 | | | | | | | |
| Stock Options - Expired | | | 15,308 | | | 122,508 | | | - | |
| Other, net | | | (17,053) | | | (11,271) | | | 18,384 | |
| Valuation Allowance | | | 739,578 | | | 393,814 | | | 618,709 | |
| Total | | $ | 36,500 | | $ | 301,431 | | $ | 16,596 | |
| | | 2017 | | 2016 | | ||
| | | | | | | | |
| Deferred tax assets | | | | | | | |
| Bad debts | | $ | 38,500 | | $ | 40,000 | |
| Intangible assets | | | 4,620 | | | 3,635 | |
| Accrued liabilities | | | 347,079 | | | 391,645 | |
| Accrued pension liability | | | 18,031 | | | 26,098 | |
| Stock options | | | 52,211 | | | 68,688 | |
| Net operating loss and credit carryforwards | | | 4,554,491 | | | 4,062,817 | |
| Total Assets | | | 5,014,932 | | | 4,592,883 | |
| | | | | | | | |
| Deferred tax liabilities | | | | | | | |
| Prepaid expenses | | | 9,179 | | | 16,173 | |
| Inventory | | | 1,057,326 | | | 1,134,160 | |
| Depreciation | | | 628,017 | | | 841,040 | |
| Other | | | 84,328 | | | 75,819 | |
| Total Liabilities | | | 1,778,850 | | | 2,067,192 | |
| Valuation Allowance | | | (2,552,319) | | | (1,812,726) | |
| Total deferred taxes | | $ | 683,763 | | $ | 712,965 | |