How to add keys/values to object with dot notation?

I am trying to use dot notation to add keys/values to my objects that I have created, but I cannot figure out how to do it. Here is my code that is not working:

    var friends = {};
    
    friends.steve = new Object();
    friends.bill = new Object();
    
    steve().firstName = 'Steve';
    steve().lastName  = 'Jobs';
    steve().number    = '555.555.1234';
    
    bill().firstName = 'Bill';
    bill().lastName  = 'Gates';
    bill().number    = '555.444.1234';

I have tried it without the parenthesis after the object name, but that does not work either.