function fadeElement(element, interval, addition, fadeMode) {
    var count = 0;
    var callback = function () {
        // countが100を超えないようにする
        count = Math.min(count, 100);
        var opacity = fadeMode ? count : 100 - count;
        // Opera, Safari, Chrome, Firefox>=3.5
        element.style.opacity = opacity / 100;
        // Firefox
        element.style.MozOpacity = opacity / 100;
        // Internet Explorer
        element.style.filter = 'alpha(opacity=' + opacity + ')';
        if (count < 100) {
            // countが100未満であれば
            // 加算
            count += addition;
            // setTimeoutに自身（関数オブジェクト）を指定
            setTimeout(callback, interval);
        }
    };
    callback();
}

function swapdivs(source, image) {
    var b = document.getElementById(source);
    var theNode = document.getElementById('main');
    theNode.style.backgroundImage = "url(images/top/" + image + ")";
    theNode.removeChild(theNode.firstChild);
    theNode.appendChild(b.firstChild.cloneNode());
    fadeElement(theNode, 12, 3, 1);
}

function swpbutton1(obj) {
    if (obj.id == "seinen") {
        document.images["seinen"].src = "images/top/news_02-1.png";
        document.images["reikai"].src = "images/top/news_03-2.png";
        document.images["kaiin"].src = "images/top/news_04-2.png";
        var theNode = document.getElementById('hoge');
        theNode.style.display = "block";
        var theNode2 = document.getElementById('fuga');
        theNode2.style.display = "none";
        var theNode3 = document.getElementById('fuge');
        theNode3.style.display = "none";
    }
    if (obj.id == "reikai") {
        document.images["seinen"].src = "images/top/news_02-2.png";
        document.images["reikai"].src = "images/top/news_03-1.png";
        document.images["kaiin"].src = "images/top/news_04-2.png";
        var theNode = document.getElementById('hoge');
        theNode.style.display = "none";
        var theNode2 = document.getElementById('fuga');
        theNode2.style.display = "block";
        var theNode3 = document.getElementById('fuge');
        theNode3.style.display = "none";
    }
    if (obj.id == "kaiin") {
        document.images["seinen"].src = "images/top/news_02-2.png";
        document.images["reikai"].src = "images/top/news_03-2.png";
        document.images["kaiin"].src = "images/top/news_04-1.png";
        var theNode = document.getElementById('hoge');
        theNode.style.display = "none";
        var theNode2 = document.getElementById('fuga');
        theNode2.style.display = "none";
        var theNode3 = document.getElementById('fuge');
        theNode3.style.display = "block";
    }
}

function swpgrid(obj) {
    if (obj.id == "seinen") {
    }
    if (obj.id == "reikai") {
        var theNode = document.getElementById('news');
        theNode.removeChild(theNode.firstChild);
        theNode.appendChild(document.getElementById('fuga'));
    }
    if (obj.id == "kaiin") {
        var theNode = document.getElementById('news');
        theNode.removeChild(theNode.firstChild);
        theNode.appendChild(document.getElementById('fuga'));
    }
}