How to limit checkbox selectable checkboxes?

Here is the code that I have compiled how ever it doesnt work.I am trying to limit selectable checkboxes with 2.

and here is the javascript code

 var limit = 2;
    $('input.civicrm-enabled.form-checkbox').on('change', function(evt) {
       if($(this).siblings(':checked').length >= limit) {
           this.checked = false;
       }
    });

Here is the html

http://ift.tt/2hatHNJ