Customize the “Enter title here” field

I love doing things well, and i love adding small details to my plugins to make them really nice. And one of the small i like to add is a quick fix to customize the “Enter title here” field in the administration, when you add a new custom post type. Here is what you normally see when you want to add a new post (page or custom post type):

But when you need to add a testimonial for example, it would be better to see something like that:

Isn’t it better ?

Well, to do this, simply use this little code, add it in your functions.php file for example or in any file of your plugin!