I have a text box that calculates price per letter. How can I get the calculation to refresh, to show the amount its going to cost, so my customers can adjust to within the price they want to pay without adding to the shop cart. If I tab out of the text box the price per letter shows but not the actual price is there a recalculate button or something I could add to improve the situation.
At present I have to add the item to the shop cart then return back to the item to see the price. I must be doing something wrong.
Any help most appreciated.

Also could anybody help me by letting me know how I can move the Add this to my cart box to the very top of the page or the very bottom of the page.
Thank you
Steve -