function CalculateValue(ol, ow, oh, ot) {
	var l, w, h;
	l = ol.value;
	w = ow.value;
	h = oh.value;
	
	if (h==0) {
		setDivText(ot, (l*w)+" square feet");
	} else {
		setDivText(ot, (2*(l*h)+2*(w*h)+(l*w))+" total square feet (including ceiling)");
	}
}
function setDivText(target, text) {
	if (target.hasChildNodes()) { 
		target.replaceChild(document.createTextNode(text), target.firstChild);
	 } else { 
		target.appendChild(document.createTextNode(text));
	}
}