code error 09 in vb 6 accounting system

[Doogle]

The method I'd use would be to store the Cost Price in Dollars in the Table, together with the %age Net Profit I want to make on each sale. At the start of the day, input the exchange rate and then calculate today's Selling Price

Selling Price [Euro] = Cost Price[Dollars] * (1 + (%age Profit / 100) * Todays Exchange Rate.

Thus if I purchased a Pen for 1 USD and wanted to make 120% Net Profit and the Euro Exchange rate was 1$ = 0.75 Euro

Selling Price = 1 * (1 + 1.2) * 0.75 Euro = 1.65 Euro

If the exchange rate changes to 1$ = 0.72 Euro the selling price would be 1.58 Euro etc.

If you're just holding the Selling Price (in Euro) in the Table, then you'll have to express the current exchange rate as a %age of the original rate (i.e the rate you used to calculate the selling price in the first place)

Thus if you're selling at 1.58 Euro, based on an exchange rate of 1$ = 0.72 Euro and the exchange rate changes to 1$ = 0.75 Euro (i.e. % difference of (0.75 - 0.72) / 0.72 = 4.166% ) you now sell at 1.58 + (1.58 * 4.166/100) = 1.65 Euro. Thus you need to store the Selling Price and the exchange rate it's based on in the Table.

ie.
Percentage Change = (Yesterday's exchange rate - Today's exchange rate) * 100 / Yesterday's exchange rate
Today's Selling Price= Yesterday's Selling Price * (1 + (Percentage Change / 100))

EDIT: It would be a 'strange' Retail Store where the Selling Prices for products changed on a daily basis - your Customers would never know how much a Pen was going to cost them. I'd be surprised if I bought a Pen from you yesterday at 1.58 Euro, today it cost me 1.65 Euro and perhaps the next day only 1.50 Euro. I expect fluctuations but not on a dialy basis. It would be a nightmare for the sales staff to go round every day changing the price tags for everything !