//学年切り替えJS

function changeCSS(sc_year) {

	var file_url = location.href;

	if(sc_year == 0 || !(sc_year >=4 && sc_year <=6)){
		file_url = file_url.substring(file_url.lastIndexOf("?")+1,file_url.length)
		sc_year = parseInt(file_url);
	//	window.alert(sc_year);
	}

	switch (sc_year){
		case 4:
			document.getElementById("4nen").style.display = "block";
			document.getElementById("5nen").style.display = "none";
			document.getElementById("6nen").style.display = "none";
			break;

		case 5:
			document.getElementById("4nen").style.display = "none";
			document.getElementById("5nen").style.display = "block";
			document.getElementById("6nen").style.display = "none";
			break;

		case 6:
			document.getElementById("4nen").style.display = "none";
			document.getElementById("5nen").style.display = "none";
			document.getElementById("6nen").style.display = "block";
			break;

	default:
			document.getElementById("4nen").style.display = "block";
			document.getElementById("5nen").style.display = "none";
			document.getElementById("6nen").style.display = "none";
	}
}