I’ve been trying to insert check boxes next to values retrieved from a MySQL table and the output is in the form of a HTML table.

The output is on the same page as the query form which will retrieve the values in the form of the table above. Now, I wish to insert check boxes beside each row/entry received from the database and use it to update the notification_sent column in the database, but so far I’ve hit a roadblock with this.
Just add one more td with the checkbox code: