Delete line(s) in external file

[motormichael12]

Okay, I have an external file that saves info in a PHP script...

<title>Links</title>
<?
$filename = 'install.php';

if (file_exists($filename)) {
echo("<META HTTP-EQUIV=Refresh CONTENT='1; URL=install.php'>");
}
if(isset($_POST['Submit']))
{
?>
<?

$dataf = "posts.txt";
$name = $_POST['name'];
$message = $_POST['message'];


if ($message != "") {$file = fopen("$dataf","a");
$write = fwrite($file,"&nbsp;&middot&nbsp;<a href=$name>$message</a>");
fclose($file);

}

?></td>
  </tr>
</table><? } ?>
<br>
<form name="guestbook" action="" method="post">
URL: <input name="name" size="50" type="text" id="name">
Link Text: <input name="message" size= "50" type="text" id="message">
<input type="submit" name="Submit" value="Submit"><input type="reset" name="Reset" value="Reset">
    </form></td>
  </tr>
</table>
<br>
<br>
<? include("posts.txt"); ?>

I need a script that will make it so there is a checkbox next to each one entered and it will allow me to delete the selected ones by clicking a submit button, like in this code...

<?php


$file = "todo.list";

$hash = sha1_file ( $file );

if ( isset ( $_POST["submit"] ) && $_POST["ohash"] == $hash ) {

    if ( $_POST["submit"] == "Add" && ! empty ( $_POST["data"]) ) {

        $fp = fopen ( $file, "a+" ) or die ("Cannot open $file for writing, check permissions");

        fwrite ( $fp, strip_tags( stripslashes($_POST["data"]),"<a><b><i><u><strong>")."\n" );
        fclose ( $fp ) ;

    } elseif ( $_POST["submit"] == "Remove" ) {

        $data = file ( $file );
        $fp = fopen ( $file , "w+" ) or die ("Cannot open $file for writing, check permissions");
        $n = 0;

        foreach ( $data as $line ) {
                
            if ( empty ( $_POST["line"][$n] ) )
                fwrite ( $fp, $line );

            $n++;
                
        }

        fclose ( $fp );


    }

    $hash = sha1_file ( "todo.list" );
}


?>
<form action="<?php echo $_SERVER["PHP_SELF"]?>" method="POST" name="todo">
<input type="hidden" name="ohash" value="<?php echo $hash ?>" />
<pre>
<?php

    $data = file ( $file );
    $n = 0;

    foreach ( $data as $line ) {

        echo "<input type='checkbox' name='line[$n]' />" ;
		echo "<a href=$place>$line</a>" ;

        $n++;

	
    }

?>
<input type="text" name="place" size="35" />
<input type="text" name="data" size="35" />
<input type="submit" name="submit" value="Add" />
<input type="submit" name="submit" value="Remove" />
</pre>
<hr />

</form>

If you can help, I would really appreciate it.

Thanks!