States populate selector

Got the states to actually populate the selector. It took some
muddling around, because I was unsure of how to create raw HTML with
jQuery, and wanted to use the .each() syntax. Turns out you just wrap
HTML text in a jQuery thingy and voila, instant HTML as a jQuery
object.
Made important fields required

Added the required attribute to the input for email, last name, and
first name.
Added address checker

Now it won't let you submit without a zipcode, if you already filled
out the address.