function validateProductDetails() {
	// ensure no more than one 'related' checkbox
	// (such as envelopes only) was checked
	var f = document.forms['order1_n'];
	var potentialErrorString = "You chose the following options\n";
	var numChosen = 0;
	for(var i = 0; i < f.elements.length; i++) {
		var e = f.elements[i];

		if (e.type != 'checkbox') {
			continue;
		}
		if (e.checked == false) {
			continue;
		}
		numChosen += 1;
		if (e.name == 'eps') {
			potentialErrorString += "\tEnvelopes Only\n";
		} else if (e.name == 'eps_dl') {
			potentialErrorString += "\tDouble-Lined Envelopes Only\n";
		} else if (e.name == 'ann_only') {
			potentialErrorString += "\tAnnouncements Only / No Envelopes\n";
		} else if (e.name == 'individual') {
			potentialErrorString += "\tGroup Order\n";
		}
	}
	if (numChosen <= 1) {
		// OK
		return true;
	} else {
		alert(potentialErrorString + "\nPlease choose at most one of those options.");
		return false;
	}
}