function checkDSPFeatures(f, message)
{
	var acAdapter = false;
	var extCord = false;

	if (typeof message == "undefined") {
		message = "You must purchase the AC Adapter with the Extension Cord.";
	}

	for (i = 0; i < f.elements.length; i++) {
		switch (f.elements[i].id) {
			case "acAdaptor":
				acAdapter = f.elements[i];
				break;
			case "extCord":
				extCord = f.elements[i];
				break;
		}
	}

	if (acAdapter && extCord) {
		if (extCord.checked && !acAdapter.checked) {
			alert(message);
			return false;
		}
	}
	return true
}