How do I add skype functions to my web environment with PHP and JS?

Say I want to create a page of PHP with HTML code of like username and password text boxes, once the user has inserted his skype username and password it will connect to skype with his details and say send me or a specific skype account a chat message and actions like that, how do I do that ?

How do I connect to skype servers in an organized way with prepared functions like log in to skype with parameters and then send chat message and things like that ?

Notice I need that in a WEB environment in PHP or JS ( I prefer PHP ).