mail liste filter

<html>
<head><title>Mail liste Filter  </title></head>
<h3>Mail liste Filter </h3>
<form method=post>
Change Here Like ( @hotmail , @live etc.. ) :<br />
<input type="text" value="@gmail" name="option"><br /><br />
<textarea name=mail cols=40 rows=20></textarea><br /><br />
<input type=submit value=Extract name=goo><br />
</form></html>
<?php

/**
 * coded by OmL33T-Dz
 * From Algeria
 * Greetz To All Freind
 * Special : Gastro_Dz , DamaneDz
 */

if(isset($_POST['goo'])){
echo "<hr>";
$maill = $_POST['mail'];
$option = $_POST['option'];
preg_match_all("/(.*)$option(.*)/i",$maill,$maillist);

foreach($maillist[0] as $mail){
echo $mail."<br>";
// file_put_contents("mail.txt", $mail."\n", FILE_APPEND);

}
// echo "done with success <a href='mail.txt'>mail.txt</a>";
}
?>