I am working on a form with a huge selection of checkboxes (certifications), arranged in a table (#certs). To make it easier for the user to check what certifications they have selected, I would like to add a list immediately following the #certs table that updates dynamically based on their selections. 

I put a paragraph under the table with a span - ID certs_list. I was able to add to this with the following code, but if the checkbox is clicked multiple times, it keeps adding the same value over and over again. How can I simply add to the list (item 1, item 2, item 3) when a checkbox is checked and remove it if it is unchecked?

$(function() { 
    $
('#c_b input[type="checkbox"]:checked').each(function() { 
        $
('#t').append(', '+$(this).val());
    
});
});