くじ引き
<p id="text" style="font-size: 200%;color: #ff0000"></p> <script type="text/javascript"> window.onload = function() { var elm = document.getElementById("text"); roulette(elm); }; function roulette(elm) { var r = Math.floor(Math.random()*10); if (r < 5) { elm.innerHTML = "アタリ"; } else { elm.innerHTML = "ハズレ"; } } </script>