window.onload = function () {
	r_change();
	num_change();
}

function r_change() {
	var R = document.getElementsByName("R");
	for (i = 0; i < R.length; i++) {
		if (R[i].checked) {
			var R_size = document.getElementsByName("R_size");
			R_size[0].disabled = R[i].value == "off";
		}
	}
}

function num_change() {
	var num = document.getElementsByName("num");
	for (i = 0; i < num.length; i++) {
		if (num[i].checked) {
			var num_parent = document.getElementsByName("num_parent");
			num_parent[0].disabled = num[i].value == "off";
		}
	}
}