title: select Onchange handling php
body: <p>PHP having function to get values of a form using
    <strong>'$_POST' for 'method=post'
    '$_GET' for <em>'method=get'</em>
    '$_REQUEST' for <em>either/both</em>.</strong> But how to handle changing value in <em>current form</em> which is <strong>not lead to form POST or GET</strong> , simply handling onchange functionality.  </p>