function offsetParentElement (element) {
      var docElement = element.ownerDocument;
      var offsetParent = element.offsetParent || docElement;
      if (nodeName(offsetParent, '#document')) return docElement.documentElement;
      while (offsetParent && !nodeName(offsetParent, 'html') && fn.css(offsetParent, 'position') === 'static') {
        offsetParent = offsetParent.offsetParent;
      }
      return offsetParent || docElement.documentElement;
    }
Returns the closest, non-statically positioned offsetParent of a given element
@required-by fn.position
@param element