// ランダムに背景画像を変更する
bgc = new Array();
bgc[0] = "url(img/random/scene1_l.gif)";
bgc[1] = "url(img/random/scene2_l.jpg)";
bgc[2] = "url(img/random/scene3_l.jpg)";
bgc[3] = "url(img/random/scene4_l.jpg)";
bgc[4] = "url(img/random/scene5_l.jpg)";
bgc[5] = "url(img/random/scene6_l.jpg)";
bgc[6] = "url(img/random/scene7_l.jpg)";
bgc[7] = "url(img/random/scene8_l.jpg)";
bgc[8] = "url(img/random/scene9_l.jpg)";
n = Math.floor(Math.random()*bgc.length);

document.getElementById('visual-area').style.backgroundImage = bgc[n]