add: return "dummy"; 
context:     function negate_comparison_type(type) {        switch(type) {            case "substring": return "notsubstring";            case "anywords":  return "nowords";            case "regexp":    return "notregexp";            default:                // e.g. "greaterthan"                 alert("Can't negate comparison type: `" + type + "'");                abort = true;        }    }
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/93046edb9a2088a288cc4bf460b66e87e3c79b4b/quicksearch.js/buggy/webtools/bugzilla/quicksearch.js