Tax Value Problem

I am new to web design and I am having a problem with tax rules.

The cart has to calculate the tax value, but since it is already included on the price item, I need the cart to state the figures as follows:

The catalogue shows: 115.00 and the cart must show this as follows:-


Sub Total £100.00
Tax £ 15.00
Total Incl Tax £115.00

I have tried adding the following rule to my cart object as previously mentioned in another successful solution.

([Price] - ([Price] * $_SESSION['tax'])) * [Quantity]

but i keep getting the error

Notice: Undefined index: Tax in d:\wamp\www\AB\WA_eCart\AngelBeeStore_PHP.php on line 368

I have included copies of the ecart images and a copy of the relevant AngelBeeStore_PHP.php code

I would appreciate any help with this matter.

The reason for that error is that the session['tax'] is not yet set. Please change your rule in eCart to be:

([Price] - ([Price] * (isset($_SESSION['tax'])?$_SESSION['tax']:"1")) ) * [Quantity]

I thank you for the quick responce in respect of this problem, but the answer have brough up a few more issues.

The formula stated as stated above:-

([Price] - ([Price] * (isset($_SESSION['Tax'])?$_SESSION['Tax']:"1"))) * [Quantity]

actually reduced the product by 100%.

I have included the following change for those looking at this query.

I have since altered the "1" and tried "0.130434" which is based on a product valued at £100 which already includes VAT/TAX of 15%

i.e. 100% for the Product + 15% for the VAT/TAX = 115%

therefore 100 / 115 = 0.869565.......
then take 1 and subtract the 0.869565
1 - 0869565 = 0.130434 <=== Suggest that this amount is stored at more than 4 decimal places as noticed that I can have a small error of 1p at 4 decimal places ===

([Price] - ([Price] * (isset($_SESSION['Tax'])?$_SESSION['Tax']:"0.130434"))) * [Quantity]

This gives the correct answer of £86.96 net price + VAT/TAX of £13.04 = £100.00

However, my problem is that the formula seems only helpful if I am dealing with one tax rate, i.e. "0.130434" unless I am missing something.

How can I set the $_SESSION['Tax'] so that I can get the relevant tax rate from a database, the tax amount can then change on which country is selected and/or state.

And so that I will not get the error due to the $_SESSION['Tax'] not being set.

Notice: Undefined index: Tax in d:\wamp\www\AB\WA_eCart\AngelBeeStore_PHP.php on line 368

From what you have said earlier I have not set the $_SESSION['Tax'] I guess that the $_SESSION['Tax'] should be setup, not within the calulations but elsewhere normally.

How do I get the TAX from a Database based on a country selected in the purchases profile, which would be far better or if not logged in no tax.

I do appreciate your time and hope that someone can help me in these matters and thanks to DANI for your earlier responce.

If the Tax Rates are stored in your database, then on your confirm page, you will need to create a record set that returns out the tax rate based on the country which is sent from your check out page. and then you will set the tax session based on the result from your record set.

If you have questions in regard to creating the record set or the session, please let me know.