Populating a new field in wp_posts table

I created a new field in the wp_posts table, called post_location. I have added fields in the post.php page and added variables and stuff everywhere I could find related to putting the information from the write form into the database, but it won’t INSERT that into the database. If I put it into the database manually I can display the information in my form field etc…but when I save again it is gone. I have done this successfully in my comments form, but can’t figure out what is missing in this post form.

Additionally if anyone knows how to write a form that would put data into this table that I could use within the blog I would also love that.