if (typeof mywebprefs == 'undefined') {
   var mywebprefs = {
      disableSS: function(ix) {
         // Disable current stylesheets
         var l = document.getElementsByTagName('link');
         for(var i=0; i< l.length; i++) {
            var a = l[i];
            var rel = a.getAttribute('rel');
            var title = a.getAttribute('title');
            if (a.id && a.id.indexOf('myss')==0) {
               a.disabled = (typeof ix != 'undefined' && a.id == 'myss'+ix) ? false : true;
            }
         }
      },
      changeMySS: function(what) {
         // Add alternate stylesheets
         var sslist = new Array(
            'http://www.abilitynet.org.uk/myway/stylesheet/mslearning.css',
            'http://www.abilitynet.org.uk/myway/stylesheet/mslearning_black.css',
            'http://www.abilitynet.org.uk/myway/stylesheet/mslearning_black_yellow.css',
            'http://www.abilitynet.org.uk/myway/stylesheet/mslearning_easy.css',
            'http://www.abilitynet.org.uk/myway/stylesheet/mslearning_yellow.css'
         );

         var el = document.body;
         var head = document.getElementsByTagName('head')[0];
         for (var i=0; i<sslist.length; i++) {
            var id = 'myss'+i;
            if (!document.getElementById(id)) {
               var newSS = head.appendChild(document.createElement('link'));
               newSS.id = id;
               newSS.rel = 'stylesheet';
               newSS.href = sslist[i];
               newSS.type = 'text/css';
            }
         }
         this.disableSS(what);
      }
   }
}
mywebprefs.changeMySS(2);