Simple PHP File Editor

php_file_editor.php

<?php
$the_file = "file.txt";

if (isset($_POST['content'])) {
    $content = stripslashes($_POST['content']);

    $fp = fopen($the_file,"w") or die ("Error opening file in write mode!");
    fputs($fp,$content);
    fclose($fp) or die ("Error closing file!");
}
?>

<form action="<?php echo $_SERVER["PHP_SELF"] ?>" method="post">
    <textarea rows="45" cols="80" name="content"><?php readfile($the_file); ?></textarea>
    <input type="submit" value="Save"> 
</form>