function calcConc(form) {
	var concAmt = 0;
	for (var i = 1; i <= 3; i++) {
		var parsecheck = "" + parseFloat(form.elements[i].value);
		if (parseFloat(form.elements[i].value) < 0 || parseFloat(form.elements[i].value) == 0 || parsecheck == "NaN") {
			window.alert("Please enter a positive number in each of the " + "three input fields.");
			return false;
		}
	}
	if (form.elements[5].checked == true) {
		concAmt = form.elements[1].value * form.elements[2].value * (form.elements[3].value / 12.0) / 27;
		form.elements[7].value = formatvalue(concAmt,7);
	} else {
		concAmt = form.elements[1].value * form.elements[2].value * form.elements[3].value / 27;
		form.elements[7].value = formatvalue(concAmt,7);
	}
	return true;
}
function calcCol(form) {
	var concAmt = 0;
	for (var i = 1; i <= 2; i++) {
		var parsecheck = "" + parseFloat(form.elements[i].value);
		if (parseFloat(form.elements[i].value) < 0 || parseFloat(form.elements[i].value) == 0 || parsecheck == "NaN") {
			window.alert("Please enter a positive number in both of the " + "two input fields.");
			return false;
		}
	}
	var radius = form.elements[2].value / 24.0;
	concAmt = form.elements[1].value * radius * radius * Math.PI / 27;
	form.elements[4].value = formatvalue(concAmt,7);
	return true;
}
function calcWall(form) {
	var concAmt = 0;
	for (var i = 1; i <= 2; i++) {
		var parsecheck = "" + parseFloat(form.elements[i].value);
		if (parseFloat(form.elements[i].value) < 0 || parseFloat(form.elements[i].value) == 0 || parsecheck == "NaN") {
			window.alert("Please enter a positive number in both of the " +
			"two input fields.");
			return false;
		}
	}
	if (form.elements[3].checked == true) {
		concAmt = form.elements[1].value * form.elements[2].value * 0.32 / 27.0;
		form.elements[6].value = formatvalue(concAmt,7);
	} else {
		concAmt = form.elements[1].value * form.elements[2].value * 0.51 / 27.0;
		form.elements[6].value = formatvalue(concAmt,7);
	}
	return true;
}
function formatvalue(input, rsize) {
	var invalid = "**************************";
	var nines = "999999999999999999999999";
	var strin = "" + input;
	var fltin = parseFloat(strin);
	if (strin.indexOf("e") != -1 || fltin > parseFloat(nines.substring(0,rsize)+".4")) {
		return invalid.substring(0, rsize);
	}
	if (strin.length <= rsize) {
		return strin;
	}
	var rounded = "" + (fltin + (fltin - parseFloat(strin.substring(0, rsize))));
	return rounded.substring(0, rsize);
}
function clearform(form,count,lastElement) {
	for (var i = 1; i <= count; i++) {
		form.elements[i].value = "";
	}
	form.elements[lastElement].value = "";
}