function checkDate(datestr) {
 // 正規表現による書式チェック
 if(!datestr.match(/^\d{4}\/\d{2}\/\d{2}$/)){
	 return false;
 }
 var vYear = datestr.substr(0, 4) - 0;
 var vMonth = datestr.substr(5, 2) - 1; // Javascriptは、0-11で表現
 var vDay = datestr.substr(8, 2) - 0;
 
 // 月,日の妥当性チェック
 if(vMonth >= 0 && vMonth <= 11 && vDay >= 1 && vDay <= 31){
	 var vDt = new Date(vYear, vMonth, vDay);
	 if(isNaN(vDt)){
		 return false;
	 }else if(vDt.getFullYear() == vYear && vDt.getMonth() == vMonth && vDt.getDate() == vDay){
		 return true;
	 }else{
		 return false;
	 }
 }else{
	 return false;
 }
}

/**
 * なめらかスクロール
 * 
 */
function smoothScroll() {
	$$('a[href^=#]:not([href=#])').each(function(element) {
		element.observe('click', function(event) {
			new Effect.ScrollTo(this.hash.substr(1), {duration: 0.2});
			Event.stop(event);
			}.bindAsEventListener(element))
	})
}

/**
 * Standards Compliant Rollover Script
 * Author : Daniel Nolan
 * http://www.bleedingego.co.uk/webdev.php
 */
function initRollovers() {
	if (!document.getElementById) return
	
	var aPreLoad = new Array();
	var sTempSrc;
	var aImages = document.getElementsByTagName('img');

	for (var i = 0; i < aImages.length; i++) {		
		if (aImages[i].className == 'rollover') {
			var src = aImages[i].getAttribute('src');
			var ftype = src.substring(src.lastIndexOf('.'), src.length);
			var hsrc = src.replace(ftype, '_on'+ftype);

			aImages[i].setAttribute('hsrc', hsrc);
			
			aPreLoad[i] = new Image();
			aPreLoad[i].src = hsrc;
			
			aImages[i].onmouseover = function() {
				sTempSrc = this.getAttribute('src');
				this.setAttribute('src', this.getAttribute('hsrc'));
			}	
			
			aImages[i].onmouseout = function() {
				if (!sTempSrc) sTempSrc = this.getAttribute('src').replace('_on'+ftype, ftype);
				this.setAttribute('src', sTempSrc);
			}
		}
	}
}