Add button that mark the post as [Solved]

I suggest to add buttom that will mark the post as [Solved].
When I wrote the first post and the solution was found, I began to look sush button but not found.
Thank to Andre, he told me how to mark the post.
As Denis Kormalev said: "I sometimes write comments like "add [solved] to your title" and is a bit tired of writing them.", so this button would make life easier for newbies and moderators too and finally it automates the process.