trouble adding class to the closest div

trouble adding class to the closest div

I am trying to write a function that when an anchor link with a particular naming convention is clicked on in a page a css class will be added to the parent div.  I'm not having any luck after hours of trying. On my test page I have two accordions. The link in the first one will jump to the text in the second one after it opens its accordion.  I don't get any errors. But my second accordion is not open and I don't see that class "in" is added to the parent div.  It's probably something obvious, but I'm a rookie at this.

My javascript is:
  1. $('a').on('click', function() {

    var href= $(this).attr('href');

    if(href.substring(0,8) === "#section")
    {
    var anchor = href.slice(1);

    alert('href is ' + href);//this works
    alert('anchor is ' + anchor); //this works
    $('#accordion .in').removeClass('in');

    $(this).closest('.collapse').addClass('in');
    //$('html,body').animate({scrollTop: $(anchor).offset().top - 65},1000);

    }

    });