PDF form w/combo box, exporting to text box, value not updating
I'm using a combo box to select different tiers of shipping methods, the export value is the cost of shipping and being populated in a text box. The text boxes Sub_Total, Shipping, and Total_Tax are summed up on the Total line. When one shipping tier is selected the script below works as it should, showing the correct export value in the shipping box. However, if a different tier of shipping is selected the total line does not update with the new shipping cost. I'm not sure how to fix the issue, any help would be appreciated.
var Shipping=this.getField("Combo Box0").value;
event.value=Shipping;
