I have a form that I do not want to pass any values to a database until submit but I want it to show the current calculation total. i.e. if someone puts the number 1 in one field and 2 in another a 'read only' field shows the number 3 in it automatically.
that is easy enough but there are a few variables.
One field will be a postcode/zipcode and will add a value to the total based on the first 2 characters entered, say they add 'ab1 2xy' the ab bit means 3 is added to the running total. how can i make this work?
any help is appreciated