I need an expandable contact form (call back form) for a word press site which needs to be located at the top of a page and scrolls with the page when user scrolls down the page. An example of the form I need is attached in the screen shot with a link to an existing site where this functionality has been used.
The main function I am interested in is that when user fills in the phone field, the form expands and additional fields appear on the contact form. I will need clear instruction on how to add the code into php, css or any other files once the design work is done. I am not looking for a wordpress widget as I need to keep my costs down but if you message me how much extra it would cost for a widget design I might also consider it depending on the price.