function getOffset(obj) {
	for( var ll=0, tt=0, oo=obj; oo; oo=oo.offsetParent) {
		tt += oo.offsetTop;
		ll += oo.offsetLeft;
	}
	return {x:ll, y:tt};
}

function getElementsByClass(className, startNode, tag) {
	var classEls = new Array();
	if(!startNode) startNode = document;
	if(!tag) tag = "*";
	var els = startNode.getElementsByTagName(tag);
	var pattern = new RegExp("(^|\\s)"+className+"(\\s|$)");
	for (var ii=0, jj=0; ii<els.length; ii++) {
		if (pattern.test(els[ii].className))
			classEls[jj++] = els[ii];
	}
	return classEls;
}