cirosec = (function () {
 return {
  changeOffset: function (element, y1, y2) {
   var el = typeof element == 'string' ? document.getElementById (element) : element;
   var y = y1;
   if (typeof y2 != 'undefined')
      y = y1 * y2;
   el.style.backgroundPosition = '0px -'+y+'px';
   return true;
   }
  };
 }) ();