function addEvent(elm, evType, fn, useCapture) {
	if (elm.addEventListener) {
		elm.addEventListener(evType, fn, useCapture);
		return true;
	} else if (elm.attachEvent) {
		var r = elm.attachEvent('on' + evType, fn);
		return r;
	} else {
		elm['on' + evType] = fn;
	}
}

function getElementPosition(elemID) {
	var offsetTrail = document.getElementById(elemID);
	var offsetLeft = 0;
	var offsetTop = 0;
	while (offsetTrail) {
		offsetLeft += offsetTrail.offsetLeft;
		offsetTop += offsetTrail.offsetTop;
		offsetTrail = offsetTrail.offsetParent;
	}
	if (navigator.userAgent.indexOf("Mac") != -1 && typeof document.body.leftMargin != "undefined") {
		offsetLeft += document.body.leftMargin;
		offsetTop += document.body.topMargin;
	}
	return {left:offsetLeft, top:offsetTop};
}

function setFreeShippingButtonPosition() {
	var divCategoryLeft = document.getElementById('categoryLeft');
	var imgFreeShipping = document.getElementById('freeShipping');

	properMarginTop = divCategoryLeft.offsetHeight - imgFreeShipping.offsetHeight - getElementPosition('freeShipping').top + getElementPosition('categoryLeft').top;
	imgFreeShipping.style.marginTop = properMarginTop + 'px';
}

addEvent(window, 'load', setFreeShippingButtonPosition, false);