sample code for undestand php file handling functions

$comment = $_POST["txtcomment"];

if ($comment!=""){

$date=date('l dS \of F Y h:i:s A');

$massage = $date.": ".$comment."\n";

$file=fopen("comment.txt","a+") or exit("Unable to open file!");

fwrite($file,$massage) or die("Could not write to file");

fclose($file);

echo "Massage sent!";

}

?>

This will write the massage to the comment.txt file.