Note 7 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2017	Mar. 31, 2016
Vacation accrual	$ 109,298	$ 118,611
Inventory reserve	81,743	90,825
Depreciation and amortization	52,378	(30,174)
Stock-based compensation deductions	86,335	115,257
Unrealized loss (gain) on marketable securities	21,852
Unrealized loss (gain) on marketable securities		(257,545)
Other	5,449	14,214
Long-term deferred tax assets	$ 357,055	$ 51,188

Deferred Tax Assets, Depreciation

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Amount of deferred tax liability attributable to taxable temporary differences due to unrealized gains on available for sale securities.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from inventory.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards classified as noncurrent.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from employee benefits, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from unrealized losses on available-for-sale securities.

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