rem: if (!box) continue; 
add: if (!box) { dump("this should not happen, things that are hidable should be in a box\n"); continue; } 
context: function hideShowControls(serverType){    var controls = document.getElementsByAttribute("wsm_persist", "true");    var len = controls.length;    for (var i=0; i<len; i++) {        var control = controls[i];        var controlName = control.id;        if (!controlName) continue;        var controlNameSplit = controlName.split(".");                if (controlNameSplit.length < 2) continue;        var controlType = controlNameSplit[0];        // skip generic server/identity things        var hideFor = control.getAttribute("hidefor");        if ((!hideFor || hideFor == "") &&            (controlType == "server" ||             controlType == "identity")) continue;        var box = getEnclosingContainer(control);        if (!box) continue;        // hide unsupported server type        // adding support for hiding multiple server types using hideFor="server1,server2"        var hideForBool = false;        var hideForTokens = hideFor.split(",");        for (j = 0; j < hideForTokens.length; j++) {            if (hideForTokens[j] == serverType) {                hideForBool = true;                break;            }        }        if ((controlType != "server" &&             controlType != "identity" &&             controlType != serverType) ||            hideForBool) {            box.setAttribute("hidden", "true");        }        else {            box.removeAttribute("hidden");        }    }    var serverPrefContainer = document.getElementById("serverPrefContainer");    if (serverPrefContainer)        serverPrefContainer.removeAttribute("hidden");}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/923fe95a7a7b4be81576123e43934a47085dbef4/am-server.js/clean/mailnews/base/prefs/resources/content/am-server.js