JavaScript Period Functionality: How do I setup a library like jQuery did

Question

Intro# (Edited)

Hey everyone, I'm setting up a JavaScript library that is designed to us AJAX and connect to a number of PHP, which then connects to the database. (fairly certain that this is what you call an API). To make things easier for my team, though, I wanted to setup some sort of initialization object like the $ in jQuery. Can someone help point me to the right data type?

Example

// Pull new user data from fields
var username = $.("#usernamefield").val();
var password = $.("#userpassfield").val();

// Send data to library through
API.AddUser(username, password);

// Sorry for any syntax errors, this is just example code

Potential Solution

I did consider using a class system, but I did some research, and it seems like there may be a better way. Can someone help explain how jQuery setup their library?

Clarificaton

A few people asked why I don't just use jQuery. Well, actually, I am. I'm using jQuery and building this separate library for uploading information with PHP. They two are Apples and Oranges, but I do want to have an initializer like jQueries "$" - Can somebody explain how they did it?

Answer 1

Here is how you should do it:

In a JS template that you could call API.js, you will have the following:

 ;(function($){

    /* ========================================================
    /* Global variables */
    /* =======================================================*/
    var api = null;

   /* ========================================================
    /* Ajax calls */
    /* =======================================================*/

    var API = function(args)
    {
        // Api methods 

        this.AddUser = function (username, password)
        {

            //To do Ajax call
        }

        this.DeleteUser = function(id)
        {
            //To do Ajax call
        }

        // ... More api methods
    };

   /* ========================================================
    /* Main function */
    /* =======================================================*/

    jQuery.fn.API = function( args )
    {
        api = new API(args);
        return api;
    };


})(jQuery);

Then when you need to make an Ajax call, you just need to initialise an API object with any required arguments as follows:

$(function() {
     //Note: you can pass global arguments.
    var API = $().API();

    //You can then make your api calls with required values

    // Pull new user data from fields
    var username = $("#usernamefield").val();
    var password = $("#userpassfield").val();

    // Send data to library through
    API.AddUser(username, password);

});