Loving the new Zoho Campaign Designer. Noticed one smallish issue with <div> and </div>:
You're adding the <div> correctly at the start of the code, and one at the end of the code, but you're adding </div> after each field, which, while most browsers will accept, isn't strict adherence to the standard and Dreamweaver complains. Here's an example where you'll see (4) </div>, one after each input field: