Append incremental

[neo_philiac]

Very simple question i have this code

<?php
$Handle = fopen("file.txt", "a+") or
    die( "Error opening file" ); 

if (!fwrite($Handle, $_POST['addition'] . "\n"))
  {
    die( "Error writing to file!" );
  } 
fclose($Handle) or
    die( "Error closing file!" ); 


?>
<form action="<?=$PHP_SELF?>" method="post">
<input type="text" name="addition"/><br/>
<input type="submit"/>
</form>

To append string into a text file with a newline. So, now if you see the text file, it looks like.

Mary 
Jane
Mark

How do I get it to increment the last (number +1) every time I append the data :

1 Mary 
2 Jane
3 Mark

Thanks

[neo_philiac]

So I got the the incremental problem fixed now that I have the data, can I create an excel file and pust the data with php? I it possible? If sp, how?