单选按钮不向MySQL数据库发布值

I have a form that is being updated by PHP to a MySQL database. I have two radio buttons:

<input type="radio" name="show_on_website" value="Y" /> Yes
<input type="radio" name="show_on_website" value="N" /> No

Upon clicking on the Yes or No radio button and submitting the form, the value Y or N, depending on which is selected does not get submitted into the MySQL database. All other data within the form is updating fine, just not the radio buttons. I am using $show_on_website = $POST['show_on_website']; upon submitting the form.

What am I missing or doing wrong? Thanks for any help you may provided.

use $_POST instead of $POST