Tax not being added to total
fortunately I solved the problem. Actually your reply was very helpful in finding out what I was doing wrong.Thank You !! it all works perfectly now.
I was 'removing' the checkout button from the cart table and adding a separate checkout button/form into that same page therefore re directing straight to Authorize net payment processing. by skipping checkout and order confirmation steps the tax rule was not applied to the total.
It is confusing , for the customer as well to see 'checkout' button in the cart and again in the checkout form. Then finally in the confirmation page it takes the customer to the payment gateway.
****I do have a new question: Is it possible, in the checkout form, to make any of the fields 'uneditable' or locked once it is sent to authorize net ? ******