A piece of code to load JS and CSS differently for desktop and mobile devices.

js_condition_load

   (function () {
        var usingMobile = false,
        userAgent = window.navigator.userAgent;

        if (/Mobile|iP(hone|od|ad)|Android|BlackBerry|IEMobile|Kindle|NetFront|Silk-Accelerated|(hpw|web)OS|Fennec|Minimo|Opera M(obi|ini)|Blazer|Dolfin|Dolphin|Skyfire|Zune/.test(userAgent)) {
            usingMobile = !/iPad/.test(userAgent); //specail for iPad                                                                                                                                         
        }   

        var sourceData = usingMobile ? RESOURCES.mobile : RESOURCES.desktop,
            head = document.getElementsByTagName('head')[0];

        for (var i = 0; i < sourceData.css.length; i++) {
            var style = document.createElement('link'),
                cssSrc = sourceData.css[i];
            style.type = 'text/css';
            style.setAttribute('rel', 'stylesheet');
            style.setAttribute('href', cssSrc);
            head.appendChild(style);
        }   
        for (var i = 0; i < sourceData.js.length; i++) {
            var script = document.createElement('script'),
                jsSrc = sourceData.js[i];
            script.type = 'text/javascript';
            script.setAttribute('src', jsSrc);
            document.write(script.outerHTML);
        }   

        if (!usingMobile) {
            var viewport = document.getElementById('pubobject-mobile-viewport');
            viewport.setAttribute('content', '');
        }   

        document.getElementById(usingMobile ? 'mobile-body' : 'desktop-body').style.display = 'block';
   })();