Welcome to the Ranch!
I think the problem is that your option elements do not have a value attribute. Option elements have two major elements:
* the value attribute, which is what will be the select's value and what will be sent to the server.
* the text (between the start and end tags), which is what you see on screen.
Since you have no value attributes, the value remains empty when sent to insert.php.
And can you please
use code tags next time? I've added them for you this time.