Hi,
I have a Book Registration Form, in which one book may have more than one authors and can belong to more than one category, therefore on the registration form, I have a textbox for the category, in order the category is not in the dropdown, I want to add that textbox value into the drop down box and the same thing for the author.

I did this, but when I refresh the page, the new category and author appears in drop down box, but I want without page refreshing.

see the attachment for more info, any idea?