想知道以下代码为什么prompt显示不出来，谢谢！
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>switch</title>
<script type="text/JavaScript">
function yourweek()
{var myweek =prompt("请输入今天星期几来查看您的日程",);//myweek表示星期几变量
switch(myweek)
{
case 1: document.write("学习理念知识");
break;
case 2: document.write("学习理念知识");
document.write("学习理念知识");
break;
case 3: document.write("学习理念知识");
break;
case 4: document.write("学习理念知识");
document.write("到企业实践");
break;
case 5:
document.write("学习理念知识");
break;
case 6:
document.write("周六、日休息和娱乐");
default:
break;
}
}
</script>
</head>
<body>
<input type="button" value="点击查询的行程" onclick="yourweek" />
</body>
</html>
