Form Php

$maxsize=28480; 
if (!$HTTP_POST_VARS['submit']) {
    $error=" ";
}
if (!is_uploaded_file($HTTP_POST_FILES['upload_file']['tmp_name']) AND !isset($error)) {
    $error = "You must upload a file!";
    unlink($HTTP_POST_FILES['upload_file']['tmp_name']);
}
if ($HTTP_POST_FILES['upload_file']['size'] > $maxsize AND !isset($error)) {
    $error = "Error, file must be less than $maxsize bytes.";
    unlink($HTTP_POST_FILES['upload_file']['tmp_name']);
}
if (!isset($error)) {
    move_uploaded_file($HTTP_POST_FILES['upload_file']['tmp_name'],
                       "uploads/".$HTTP_POST_FILES['upload_file']['name']);
    print "Thank you for your upload.";
    exit;
}
else
{
    echo ("$error");
}
?>



"
method="post" enctype="multipart/form-data">
    Choose a file to upload: