I have a checkout page that was built where a user enters all information needed to purchase a product.  Well I need to add a state tax depending on which one is selected.  I am having trouble getting this to work.  I created a hidden dynamic field with the Short Name "txtTax", the corresponding field is a dropdown box with the list of states in it.  For a client side event on the hidden field I have:

if($(txtState)=="Ohio")

{

$(txtTax) = 6.68

}

else

{

$(txtTax) = 0;

}

At first I tried putting this in the state client side script but It would give me an error.  Now in the Payment Gateway, I have my calculation total set as 99+$(txtTax).  It doesn not seem to be working, does anyone know a better way to handle this or why this isnt working?