Limit HTML checkbox selections

HTML_checkbox_limiter.js

<script type="text/javascript">
    // Limit the number of checkboxes that can be selected at one time
    var checkboxLimit = 3;
    var questionTolimit = 'q3';

    $("input[type=checkbox][name="+questionTolimit+"]").click(function() {
        var checkTest = $("input[type=checkbox][name="+questionTolimit+"]:checked").length >= checkboxLimit;
        $("input[type=checkbox][name="+questionTolimit+"]").not(":checked").attr("disabled",checkTest);
    });
</script>