this.offset = this.cumulativeOffset(element); 
this.offset = Element.cumulativeOffset(element); 
  within: function(element, x, y) {    if (this.includeScrollOffsets)      return this.withinIncludingScrolloffsets(element, x, y);    this.xcomp = x;    this.ycomp = y;    this.offset = this.cumulativeOffset(element);    return (y >= this.offset[1] &&            y <  this.offset[1] + element.offsetHeight &&            x >= this.offset[0] &&            x <  this.offset[0] + element.offsetWidth);  },
4053	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/4053/37a06e5ed1bdb861348bb0cfd02f71470a0dfdfb/prototype.js/clean/lib/prototype.js