1. We show validation-infos for email, if email has false format, or empty (after edit). 2. If You click "agree", we show the new input field for "sign". 3. You can save valid input and reset later to it.
Angular provides basic implementation for most common html5 input types (text, number, url, email, radio, checkbox) as well as some directives for validation (required, pattern, minlength, maxlenght, min, max).