authentication to https server

hi I have a question here. This is what i want to do: I have a login/password form, in order to make the password going through the network (from client's browse to the server) secure, I need to run https server on the server side. Here is my problem: How do I do the authentication? Originally, without https, I just check the username/password POST from the client's browser with the database, and session_register()/session_start(). But how do I approach this in https? The https/DB are running on the same machine that hosts the login/password form. I understand I could use curl libraries to do post. But what would the url required in curl functions be? Thanks in advance. Wei