var imglist = new Array(
 'ikuA.swf',
 'ikuB.swf',
 'ikuC.swf' );

var selectnum = Math.floor((Math.random() * 100)) % imglist.length;
   //var output = "<img src=" + imglist[selectnum] + ">";
document.open();
document.writeln(
 '<object width="650" height="433" data="http://www.ikutouen.com/flash/' + imglist[selectnum] + '" type="application/x-shockwave-flash"><param name="src" value="http://www.ikutouen.com/flash/' + imglist[selectnum] + '" /></object>');
document.close();