Autotab

Autotab.js

$.fn.autotab = function () {
    var inputEvents = "input";
    if (!("oninput" in document || "oninput" in $("<input>")[0])) {
        inputEvents += " keypress";
    }
    return this.each(function () {
        var $this = $(this);
        $this.on(inputEvents, "input[maxlength]", function (e) {
            var $this = $(this);
            if ($this.attr("maxlength") <= $(this).val().length) {
                $this.focusNextField();
            }
        });
        return this;
    });
};

$.fn.focusNextField = function () {
    return this.each(function () {
        var $this = $(this);
        var elements = $(this).parents('div.line').find('input');
        var index = elements.index(this);
        if (index > -1 && (index + 1) < elements.length) {
            elements.eq(index + 1).focus().on("keydown", function (e) {
                if (!$(this).val().length) {
                    if (e.which == 8) {
                        $this.focus();
                        $this.val(function () {
                            return $this.val();
                        });
                    }
                }
            });
        }
        return this;
    });
};