the goal is auto fill in fields in res.partner from website, for example we fill in code of the company and then other fields are auto filling from website where all data of the company is stored.

So what approach i should take

My thought process is like this. i need to make a controller that fills other fields in form...  if anyone have a clue what i'm talking about, maybe you can give me some example.. or pseudo code.. just to get a whole picture..  because i haven't touched controllers before...