With this line php tries to remove the file specified by the variable $all.
If that fails the variable $noerrors is set to false and the error variable $errors inside the class is set to a value that tells you which file it wasn't able to delete.
If $noerrors is one of the global variables in that class it should be $this->noerrors instead of $noerrors;
I'm not sure if that code is correct at all. I can't test it now but I'm not sure. It might be that the $this->errors = ".." part of the code will be done even if the unlink was successful.
It could be better to have something like:
if (!@unlink($all)) {
$noerrors=false;
$this->errors = "Upload class save error: unable to overwrite ".$all."<BR>";
}
Just a suggestion, depends on the code 🙂