<form action='http://eletters.xxxx.xx/subscription.php' method='post' target='pmnlwindow' onsubmit="window.open('http://eletters.xxxx.xx/subscription.php', 'pmnlwindow', 'scrollbars=yes,width=700,height=210');return true">
<div class="input-group margin-bottom-sm">
<span class="input-group-addon"><i class="fa fa-envelope-o fa-fw"></i></span>
<input class="form-control" type="text" name='email_addr' value='' size='30' placeholder="Email address">
</div>
<input type='hidden' name='list_id' value='4'>
<input type='hidden' name='op' value='join'>
<input class="btn btn-default btn-sm" type='submit' value='souscrire'>
</form>