文件上传问题

<?
print_r($_FILES);
print_r($HTTP_POST_FILES);
?>
<form name="form" enctype="multipart/form-data" method="post" action="">
<table border="1">
<tr>
   <td align="right">
       附件:
   </td>
   <td>
       <INPUT type="file" name="file">
   </td>
</tr>
<tr>
   <td align="center" colspan="2">
       <input type="submit" name=submit value="发送">
   </td>
</tr>
</table>
</form>
</CENTER>