The Facebook staff is always on the move to evolve, experiment and add new features to the social network. What I love about them is the way they do it. Apart from the timely major over-hauls, they keep on introducing users to minor changes and updates. This allows users to cope up with changes while getting to enjoy new features at the same time.
Facebook recently updated the commenting system and secretly slipped a new feature along. The new commenting system doesn’t have the submit comment button instead you just have to press Enter key to submit your comment. The secretly slipped new feature allows you to edit the comments once they are submitted. That can be done by using the "X" button on the right top corner of your comment. The "X" button will act as edit comment button if the comment is less than a minute old or no one has commented after you. If either of that happens, your comment will be locked and "X" will act as delete comment.
Editing comment will also notify all those who have previously commented or liked the post.