I have a purchase order form that is using the script from the Purchase order example in the help files to calculate the quantity x price in the table, and then to add the resulting subtotal(s) along with the tax and shipping (fields outside the table) to get a grand total.

The problem I have is that the tax and shipping fields are being duplicated based on the number of items added to the table.  If I show tax and shipping at $1.00 each and I have only one line in the table, the calculation is accurate.  If I have two lines in the table, tax and shipping calculate at $2.00 each when added to the grand total, and they increase incrementally with each line added to the table.  

Can someone tell me what to modify in the script so that the tax and shipping are calculated without regard to the number of lines in the table?  I also have some script at the top to hide a field when the form loads.

Thank you!!