请问输入一样的数字也是错误怎么回事？
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Math </title>
<script type="text/javascript">
var a=confirm(Math.round(Math.random()*10));
var b=prompt("请输入验证码");
if (a==b){
confirm("正确");
}
else{
confirm("错误");
}
</script>
</head>
<body>
</body>
</html>
