var count;
function BackgroundChange(){
var color = Math.floor(Math.random() * 0xFFFFFF).toString(16);//#RRGGBBを取得
for(count = color.length; count < 6; count++){
color = "0" + color;     //上位に0を補完する
}
color = "#" + color;             //最上位に#を付ける
if(window.opera){
document.body.style.backgroundColor = color;//背景色変更
}else{
document.bgColor = color;//背景色変更
}
}
window.onload = BackgroundChange;