I just setup my first Ubuntu server and things were going smoothly until I realized that my tiny php script:

<?php
    // write email to a file
    if (isset($_POST['email'])) {
        $myfile = fopen("emails.txt", "a") or die("Unable to open file!");
        $txt = $_POST['email']."\n";
        fwrite($myfile, $txt);
        fclose($myfile);
    }
?>

was no longer working... I poked around the help boards, but couldn't find any articles that were hand-holdy enough to get me a solution. Wondering if anyone can help!