file save not working

[Tex]

Hello again, I am trying to save an uploaded file to my LAMP server,
and I can upload the file just fine into the tmp folder, but the move_uploaded_file function isn’t working. I suspect it has something to do with permissions? Here is my code:
HTML:
[php]

Filename:
[/php] upload_file.php [php] <?php if ((($_FILES["file"]["type"] == "image/gif") || ($_FILES["file"]["type"] == "image/jpeg") || ($_FILES["file"]["type"] == "image/pjpeg")) && ($_FILES["file"]["size"] < 20000)) { if ($_FILES["file"]["error"] > 0) { echo "Return Code: " . $_FILES["file"]["error"] . "
"; } else { echo "Upload: " . $_FILES["file"]["name"] . "
"; echo "Type: " . $_FILES["file"]["type"] . "
"; echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb
"; echo "Temp file: " . $_FILES["file"]["tmp_name"] . "
";

if (file_exists("upload/" . $_FILES["file"]["name"]))
  {
  echo $_FILES["file"]["name"] . " already exists. ";
  }
else
  {
  move_uploaded_file($_FILES["file"]["tmp_name"],
  "upload/" . $_FILES["file"]["name"]);
  echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
  }
}

}
else
{
echo “Invalid file”;
}
?>
[/php]