week03a3.html

変わる色を設定ー＞配列で色を定義しておく．
背景色は document.bgColo=で変更
時間はsetTimeoutで設定


<html>
<head>
 <title>week03a3.html</title>
 <script type="text/javascript">
    var iroset=new Array("red","yellow","green","blue");
    var bango = 0;
    function iro(){
       document.bgColor=iroset[bango];
       bango += 1;
       if( bango > 3 ){
          bango = 0;
       }
       setTimeout("iro()",1000);
    }
 </script>
</head>
<body>
 <form>
  <input type="button" value="what color?" onclick="iro()">
 </form>
</body>
</html>