Synchronizes Select Dropdowns - jQuery

synchronizedDropdownsLol.js

    $(function(){
        $('.testSubjectSelect').change(function() {
            var selectedValues = $("option:selected").map(function(){return this.value;});

            $('.testSubjectSelect').children('option').not(":contains('-Select a Subject-')").each(function() {
                if ($.inArray($(this).val(), selectedValues) > -1 && !this.selected) {
                    $(this).attr('hidden', true);
                } else {
                    $(this).removeAttr('hidden');
                }
            });
        })
    });