$(document).ready(function() { 
    $("#members_table").tablesorter({ 
        // pass the headers argument and assing a object 
        headers: { 
            // assign the first column (we start counting zero) 
            0: { 
                // disable it by setting the property sorter to false 
                sorter: false 
            }, 
            // assign the fourth column (we start counting zero) 
            4: { 
                // disable it by setting the property sorter to false 
                sorter: false 
            } 
        } 
    }); 
});