//use this to add a form var called $newThing to a file.
$file = "/www/htdocs/yourFile.txt";
$fp = fopen($file,"a");
fputs($fp,"$newThing\n");
fclose($fp);
//then you can make a new file that opens that file with the form data, counts line by line, and returns a value of how many lines there are.
$lines = file("./www/htdocs/yourFile.txt");
$myCount= count($lines);
echo "Count = $myCount<br>";
fclose($fp);
something like that anyway...
hope it helps.
-Dan