如何限制上传文件的类型?
文件如下:
<html>
<head>
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>file</title>
</head><body>
Please select a file:<input type="file" name="file1">
</body>
</html>
当点击浏览按钮时,怎样限制文件类型为word文档或别的类型的文档?