function countdown() {
	var target_day = new Date(2009, 8 - 1, 23);	// ２００９年８月２３日
	var today = new Date();
	
	var days = Math.floor((target_day-today)/(24*60*60*1000));
	var hours = Math.floor(((target_day-today)%(24*60*60*1000))/(60*60*1000));
	var minutes = Math.floor(((target_day-today)%(24*60*60*1000))/(60*1000))%60;
	var seconds = Math.floor(((target_day-today)%(24*60*60*1000))/1000)%60%60;
	
	var text = "<a href='http://ice-ribbon.ne07.jp/' target='new'>アイスリボン</a>後楽園大会まで、あと"+days+"日"+"と"+hours+"時間"+minutes+"分"+seconds+"秒！"
	if((target_day - today) > 0){
		document.getElementById("message").innerHTML = text;
	} else {
		document.getElementById("message").innerHTML = "<font size='5'><a href='http://ice-ribbon.ne07.jp/' target='new'>アイスリボン</a>後楽園大会<font color='red'>当日</font>です！！</font>";
	}
	
	tid = setTimeout('countdown()', 1000);
}