Wants PHP script for subscription

Hello Everyone
I purchased Eve – Responsive Underconstruction Theme from themeforest.
But they don’t provide php script for subscription.when i contact them on theme forum they say that is not our work.However they told me,i have to create PHP script in process.php file.
As,i am new to php i don’t know what to change in process.php file so that mail can receive when anybody subscribe.
This is the code in process.php :
<?php

//Retrieve form data.
//GET – user submitted data using AJAX
//POST – in case user does not support javascript, we’ll use POST instead
$email = ($_GET[’email’]) ?$_GET[’email’] : $_POST[’email’];

//flag to indicate which method it uses. If POST set it to 1
if ($_POST) $post=1;

//if the errors array is empty, send the mail / no errors found
if (!$errors) {

//if POST was used, display the message straight away
if ($_POST) {
echo ‘Thank you! We have received your message.’;

//This one for ajax
//1 means success, 0 means failed
} else {
echo ‘1’;
}

} else {
//display the errors message
for ($i=0; $i<count($errors); $i++) echo $errors[$i] . ‘
‘;
echo ‘Back‘;
exit;
}

?>