rem: while (sep = sep.nextSibling) { 
add:  while ((sep = sep.nextSibling)) { 
context: function checkFocusedWindow(){  var windowManager = Components.classes['@mozilla.org/rdf/datasource;1?name=window-mediator'].getService();  var windowManagerInterface = windowManager.QueryInterface(Components.interfaces.nsIWindowMediator);  var sep = document.getElementById("sep-window-list");  while (sep = sep.nextSibling) {    var url = sep.getAttribute('id');    var win = windowManagerInterface.getWindowForResource(url);    if (win == window) {      sep.setAttribute("checked", "true");      break;    }  }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/b24bff35a93037ee606c332cbf9cb77ac0adaa23/tasksOverlay.js/clean/suite/common/tasksOverlay.js