gistfile1.js

function Hello(name) {
    // create context
    var my = {};
    my.name = name || 'you';
    
    // define methods
    function greet(name) {
        name = name || my.name;
        alert('Hello '+name+'.');
    }

    // create instance
    var instance = function(name) {
        greet(name);
    }
    
    // populate instance
    instance.greet = greet;

    return instance;
}

var h1 = new Hello('World');
var h2 = new Hello('Larry');

//alert(h1 instanceof Function); // true
h1();
h2();
h2('everybody');
h1.greet('Dolly');