/**
 * 自動画像切り替え処理
 *
 * @param name 属性名
 * @param file ファイル名
 */



var imgId = 0;
var timerID;
var iName = 'artMain';
var beforeID = undefined;

function intervalImg() {
	var autoImgs = document.getElementsByName("flashImg");
	var len = autoImgs.length;
	timerID = setTimeout('intervalImg()',5000);
	imgId = getImgId(len);
	document[iName].src = autoImgs[imgId].getAttribute("imgSrc");
}

function stopInterval() {
    clearTimeout(timerID);
    timerID = undefined;
}

function startInterval() {
    if( timerID == undefined ) {
	    var autoImgs = document.getElementsByName("flashImg");
	    var len = autoImgs.length;
		imgId = getImgId(len);
        timerID = setTimeout('intervalImg()',5000);
    }
}

function getImgId(length) {
	if( length == 1 ) return 1;

	newId = Math.floor(Math.random()*length);
	if( newId == imgId ) {
		newId = getImgId(length);
	}
	
	return newId;
}

window.onload = function(){
    intervalImg();
}