php上传问题~~~~

源代码：
<?php
if(is_uploaded_file($_FILES['upfile']['tmp_name'])){
$upfile = $_FILES["upfile"];
$name = $upfile["name"];
echo $name;
$size = $upfile["size"];
$type = $upfile["type"];
$tmp_name = $upfile["tmp_name"];

move_uploaded_file($tmp_name,'up/'.$name);
}
?>


  <form action="" method="post" enctype="multipart/form-data">
  上传文件：<input type="file" name="upfile" size="40"/>
  <input type="submit" value="上传"/>

  </form>

我上传一个《名师-讲坛.gif》文件
错误信息
Warning: move_uploaded_file(up/名师-讲坛.gif) [function.move-uploaded-file]: failed to open stream: No such file or directory in F:\ke\BBS\up.php on line 10

Warning: move_uploaded_file() [function.move-uploaded-file]: Unable to move 'F:\wamp\tmp\php6D9.tmp' to 'up/名师-讲坛.gif' in F:\ke\BBS\up.php on line 10
在线等高手解答！！！

上传的文件不存在无法执行你那个move的移动函数 请检查文件是否存在或者路径是否正确。

检查当前up文件夹是否存在。