I've pasted the code to my web page but it keeps redirecting to the errror page. This is the page-
Any advice would be greatly appreciated.
I tried your page and I was able to add an email address that was probably not already in your account without a problem, I as directed to the success page. However, when I tried to put that email address in again it gave me an error.
Our API's are designed so that you cannot add a contact that already exists. This is done with a seperate Update call to the Contacts Collection API.
It appears you are using our Constant Contact Signup Form Generator to create the signup form. At this time, the signup form generator does not have the Update functionaity built in. While this can be created using our API, it does require knowledge of a scripting language to do this.