rem:  this.throbber.setAttribute("busy", true); 
add:  if (this.throbber) this.throbber.setAttribute("busy", true); 
context:   _startMeteors : function()    {      this.ensureStatusFields();      this.meteorsSpinning = true;      this.startTimeoutID = null;      // Turn progress meter on.      this.statusBar.setAttribute("mode","undetermined");      // turn throbber on      this.throbber.setAttribute("busy", true);      //turn on stop button and menu    this.stopCmd.removeAttribute("disabled");    },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/2700170bb66d95f07aba77df19bcf3f69e8796bf/mailWindow.js/clean/mailnews/base/resources/content/mailWindow.js