JS - isMobile / isTablet / isDesk

ismobile.js

//Global function
if (!window.Nsw) {
    window.Nsw = {};
}

Nsw.viewPortWidth = function() {
    var e = window, a = 'inner';
    if (!('innerWidth' in window )) {
        a = 'client';
        e = document.documentElement || document.body;
    }
    return e[ a+'Width' ];
};

Nsw.isMobile = function () {
    return Nsw.viewPortWidth() < 768;
};
Nsw.isTablet = function () {
    return Nsw.viewPortWidth() >= 768 && Nsw.viewPortWidth() < 1024;
};
Nsw.isDesktop = function () {
    return Nsw.isMobile() == false && Nsw.isTablet() == false;
};