change string with jquery
replace some value in action attribute
by mobilat
HTML
<script src="https://code.jquery.com/jquery-2.2.4.min.js"></script>
<form name="filter" class="form" action="/index.php?id=5&tx_femanager_pi1%5Bcontroller%5D=User" method="post">
JavaScript
var myFormAction = $('.form').attr('action');
var myString = myFormAction.substr(myFormAction.indexOf("&") + 1);
var myNewAction = $('.form').attr('action', '/index.php?id=170&' + myString);
alert(myNewAction);