var txt = new Array();
txt[0]="img/top/kisyouIlust01.jpg";
txt[1]="img/top/kisyouIlust02.jpg";
txt[2]="img/top/kisyouIlust03.jpg";
txt[3]="img/top/kisyouIlust04.jpg";
txt[4]="img/top/kisyouIlust05.jpg";

mmax = 5; //メッセージ行数
txtno = Math.floor(Math.random() * mmax);
document.write('<img src="'+ txt[txtno] +'" width="194" height="84" />');