onchange event for dropdownlist

Question

<script type="text/javascript">

function TextChange() {

debugger

var values = $(document.getElementById('#MainContentcourse')).val();

{

if (values = 'B.Tech[PCB Group]') {

$('#divtenper').show();

$('#divyear10').show();

$('#divpertwelth').show();

$('#divyearof12').show();

$('#divgraper').hide();

$('#divyearofgra').hide();

}

var values = $(document.getElementById('#MainContentcourse')).val();

 

i got undefined value