PHP文件上传，在一台机器上工作正常但在其他机器上没有？

While I was trying to uplaod file using php on windows machine its working fine :

   <form action="php/bulk.php"
  enctype="multipart/form-data" method="post">
  <p>
   Please specify a file below:<br>
  </p>
    <div>
  <input id="datafile" type="file" name="datafile" size="40"><br>
  <input type="submit" value="Upload File">
 </div></form>

code on bulk.php :

$connector = new DbConnector();
$target_path = "uploads/";
$target_path = $target_path . basename( $_FILES['datafile']['name']);

if(move_uploaded_file($_FILES['datafile']['tmp_name'], $target_path)) {
  echo "The file ".  basename( $_FILES['datafile']['name']).
  " has been uploaded.  
";

} else{
echo "There was an error uploading the file, please try again!";
?>
<form action="../addsamples.php">
 <input type="submit" value="Go Back" />
</form>
<?php
    exit (-1);
}

I tried uploading on server and its not working there ! Do Operating system play any role in this ? My server is red hat linux and test m/c is windows

The most likely problem is the file-permissions. Does the user that is running the web-server (apache I think for red hat) have write-permissions for php/uploads/?