function addEventListener(target, type, func) {
  if (!target) return;
  if(target.attachEvent) {
		target.attachEvent("on" + type, func);
	} else if(target.addEventListener) {
		target.addEventListener(type, func, true);
	} else {
	  target["on" + type] = func;
	}
}

function requiredCheckA(e){
	var elem = (e.target)? e.target : e.srcElement ;

	if(elem.landingArea.value == "" || elem.area.value == "" || elem.country.value == "" || elem.city.value == ""){
		alert('目的地(地域・国・都市)は必須条件です');

		if(window.attachEvent) {
			event.returnValue = false;
		} else if(window.addEventListener) {
			e.preventDefault();
		}

		return false;
	}
}

function requiredCheckT(e){
	var elem = (e.target)? e.target : e.srcElement ;

	if(elem.landingArea.value == "" || elem.area.value == "" || elem.country.value == ""){
		alert('目的地(地域・国)は必須条件です');

		if(window.attachEvent) {
			event.returnValue = false;
		} else if(window.addEventListener) {
			e.preventDefault();
		}

		return false;
	}
}