I'd like to add an autocomplete system to my website, I searched for a while but I didn't find what i'm looking for, it's hard to explain.

I'd like a system that autocomplete the input directly inside itself. Google use a "general" autocomplete plus this one but it seems nobody else has worked on something like this !

Something simple, and logical ... And if doesn't exist, how is it possible to do something like this ?

Here's the google system:

[google autocomplete inside input](http://i.stack.imgur.com/unaOQ.png)