Hey all! Happy new years!

I was having some difficulty trying to get this one figured out and I was hoping I could get some pointers on the board.

Here is my form:

http://www.mykesdesigns.com/jwservices.jpg
Pretty basic...

In the bottom left, starting with "Subtotal" it is getting its total from "Service Charge" , "Mileage Charge" which is .40 cents multiplied by the number of miles in the "Mileage Field" and "misc. Charge" all summed together.

THEN the "Sales Tax" field is automatically populated by taking .0592 multiplied by the "Subtotal" field.

Then of course the "Total Amount" is the "Subtotal" and the "Sales Tax Charge" Summed together.

What I wanted is to be able to check a box that is a "No sales tax" box that would exclude "Sales Tax Charge" from the "Total Amount" field.

If I cant find a way to do this. I will just create two Total amount fields, but I though this would be a much slicker way of presenting this in the end.

Any help is much appreciated. Thanks a bunch!