输出无反应
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
<title>prompt</title>
<script type="text/javascript">
var myname=prompt("请输入你的姓名:");
if(myname!=null)
{ alert("你好"+myname); }
else
{ alert("你好 my friend."); }
}
</script>
</head>
</html>