Creating a simple JavaScript class with jQuery

I'm trying to understand jQuery classes but it is not going very well.

My goal is to use a class this way (or to learn a better way to do it):

var player = new Player($("playerElement"));
player.InitEvents();

Using other people's examples, this is what I tried:

$.Player = function ($) {

};

$.Player.prototype.InitEvents = function () {

    $(this).keypress(function (e) {
        var key = e.which;
        if (key == 100) {
            MoveRight();
        }
        if (key == 97) {
            MoveLeft();
        }
    });
};

$.Player.prototype.MoveRight = function () {
    $(this).css("right", this.playerX += 10);
}

$.Player.prototype.MoveLeft = function () {
    $(this).css("right", this.playerX -= 10);
}

$.Player.defaultOptions = {
    playerX: 0,
    playerY: 0
};

The end goal is to have a character moving on the screen left and right using the keyboard letters A and D.

I have a feeling that I'm doing something very wrong with this "class" but I'm not sure why.

(sorry for my English)