show DIV once selected option PASS from drop down menu
===

I would like to create simple drop down with options and one of the will be PASS then show DIV once selected option PASS from drop down menu, for other options DIV will be closed

    <script type="text/javascript">
    function changetextbox()
    {
        if (document.getElementById("mfi_4_a_i").value === "noy") {
            document.getElementById("PASS").disable='true';
        } else {
            document.getElementById("sdd").disable='false';
        }
    }
    </script>