var headerImgBoxName = "imagebox";
var headerImgName = "headimages";
var browsSeconds = 10;
var opacityGrade = 2;
var imgOpacity = 100;
var randomImg = 0;
var photos = new Array(
	"common/top-img/topimage01.jpg",
	"common/top-img/topimage02.jpg",
	"common/top-img/topimage03.jpg",
	"common/top-img/topimage04.jpg",
	"common/top-img/topimage05.jpg"
);


function headerRotate() {
	randomImg = Math.floor(Math.random() * photos.length);
	document.write('<img id="headimages" width="750" height="167" src="' +photos[randomImg] + '" />');
}


function headerAnimation() {
	var imgObj = document.getElementById(headerImgName);
	document.getElementById(headerImgBoxName).style.backgroundImage = 'url(' + photos[randomImg] + ')';
	imgFade();
}


function imgFade() {
	var imgObj = document.getElementById(headerImgName);
	if (imgOpacity <= opacityGrade) {
		imgOpacity = 100;
		imgSelect();
		setTimeout("imgFade()",browsSeconds*1000);
	}else{
		imgOpacity -= opacityGrade;
		setOpacity(imgObj,imgOpacity);
		setTimeout("imgFade()",50);
	}
}


function imgSelect() {
	var divObj = document.getElementById(headerImgBoxName);
	var imgObj = document.getElementById(headerImgName);
	imgObj.src = photos[randomImg];
	setOpacity(imgObj,100);
	randomImg = Math.floor(Math.random() * photos.length);
	divObj.style.backgroundImage = 'url(' + photos[randomImg] + ')';
}


function setOpacity(obj, opacity) {
	opacity = (opacity == 100)?99.999:opacity;
	obj.style.filter = "alpha(opacity:"+opacity+")";	
	obj.style.KHTMLOpacity = opacity/100;
	obj.style.MozOpacity = opacity/100;
	obj.style.opacity = opacity/100;
}

window.onload = headerAnimation; 


function print_out() {
   /* print() が使えるブラウザかどうかを判断 */
   if (navigator.userAgent.match(/msie (\d)/i))
      v = (eval(RegExp.$1) >= 5) ? 1 : 0;
   else if (self.innerWidth)
      v = (eval(navigator.appVersion.charAt(0)) >= 4) ? 1 : 0;
   else v = 0;

   /* print() が使えるブラウザなら印刷を実行 */
   if (v) self.print();
   else alert("お使いのブラウザではこの機能は利用できません");
}