var iValue, rNumber;

var img1 = new Image();
var img2 = new Image();
var img3 = new Image();
var img4 = new Image();
var img5 = new Image();
var img6 = new Image();
var img7 = new Image();

img1 = "img/top01.jpg";
img2 = "img/top02.jpg";
img3 = "img/top03.jpg";
img4 = "img/top04.jpg";
img5 = "img/top05.jpg";
img6 = "img/top06.jpg";
img7 = "img/top07.jpg";

//乱数で表示する画像を決めます。ここでは画像が４枚なので乱数は４種類必要になります。
function display_image(){
	iValue = Math.random() * 7;
	rNumber = Math.ceil(iValue);
	if(rNumber == 0){ rNumber++; }
	document.sotoyu.src = eval("img" + rNumber);
}