javascript alert乱码的解决方法

echo '<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />';
echo '<script type="text/javascript">alert("添加成功")</script>';

<script language="javascript" type="text/javascript" src="ntkoocx.js"></script>

<script charset="gb2312" language="javascript" type="text/javascript" src="ntkoocx.js"></script>