How add Username (u_name) to order email

How add Username (u_name) to order email

Hi

can you please help me add to orderemail.php template

order user username ?

a have add to orderemail.php
++++++
Your username is : <?php $user = JFactory::getUser(); echo $user->username;?><br>
++++++
but if i resent order email fom backend i have admin username not username from user order.

pleas help