Object.prototype.nextObject = function() {
	var n = this;
	do n = n.nextSibling;
	while (n && n.nodeType != 1);
	return n;
}
 
Object.prototype.previousObject = function() {
	var p = this;
	do p = p.previousSibling;
	while (p && p.nodeType != 1);
	return p;
}