var imglist = new Array(
      "/img/img_rcp_01.jpg",
      "/img/img_rcp_02.jpg",
      "/img/img_rcp_03.jpg" );
   var selectnum = Math.floor((Math.random() * 100)) % imglist.length;
   var output = "<img src=" + imglist[selectnum] + " alt='レモンのチカラをいかしたレシピ' border='0' width='77' height='82'>";
   document.write(output);