function focusDoubleDo() {
	if (!document.getElementsByTagName) return false;
	var doubleDo = document.getElementsByName('doubleDo');
	for (var i=0; i<doubleDo.length; i++) {
		doubleDo[i].onclick = function() {
			checkDouble('double');
		}
	}
}
addLoadEvent(focusDoubleDo);

function checkDouble(NAME){
	var DoubleList = document.getElementsByName(NAME);
	var DO = document.getElementsByName('doubleDo');
	if(DO[0].checked == true) {
		for (var i=0; DoubleList.length; i++) {
			DoubleList[i].disabled = false;
		}
	} else if(DO[1].checked == true){
		for (var i=0; DoubleList.length; i++) {
			DoubleList[i].checked = false;
			DoubleList[i].disabled = true;
		}
	}
}