var Opera = (navigator.userAgent.indexOf('Opera') != -1);
var MSIE = (navigator.userAgent.indexOf('MSIE') != -1);
var Moz = (navigator.userAgent.indexOf('Gecko') != -1);

if ((Opera && MSIE) || Opera) {
  var Opera = true;
  MSIE = false;
}

if (MSIE && !Opera) {
  MSIE = true;
}