If all you need is the contents of a form emailed to you, there are a lot of scripts that will do this for you. http://hotscripts.com will have them, including several that are free. If you need one that accept the input, create the coupon and email that to the user you'll need to do some additional work (how much depends on what the finished product looks like) and you're likely have to get a programmer to do that (although you might be able to have the form input added to a template you make without having to do so).