Add and Remove Style Sheet at Runtime in Javascript

function AddstyleSheets () {

 var cssNode = document.createElement('link');

            cssNode.type = 'text/css';

            cssNode.rel = 'stylesheet';

            cssNode.href = '<%: Url.Content("~/Content/css/index.css")%>';

            cssNode.media = 'screen';

            cssNode.title = 'dynamicLoadedSheet';

            document.getElementsByTagName("head")[0].appendChild(cssNode);

}

function RemovestyleSheets () {

            var styleSheets = document.styleSheets;

            var href = '<%: Url.Content("~/Content/css/index.css")%>';

          

            for (var i = 0; i < styleSheets.length; i++) {

               if (styleSheets[i].href == href) {

                  styleSheets[i].disabled = true;

                    break;

                }

            }

        }