add:  #ifdef MOZ_WIDGET_GTK2    var mapiReg; try { mapiReg = Components.classes["@mozilla.org/mapiregistry;1"]. getService(Components.interfaces.nsIMapiRegistry); } catch (e) {} if (!mapiReg) { document.getElementById("defaultClientBox").hidden = true; return; } #endif 
context: function Startup(){  var startupFunc;  try {    startupFunc = document.getElementById("mailnewsEnableMapi").getAttribute('startupFunc');  }  catch (ex) {    startupFunc = null;  }  if (startupFunc)    eval(startupFunc);  StartPageCheck();  // now do some Notification panel startup work:   PlaySoundCheck();  // if we don't have the alert service, hide the pref UI for using alerts to notify on new mail  // see bug #158711  var newMailNotificationAlertUI = document.getElementById("newMailNotificationAlert");  newMailNotificationAlertUI.hidden = !("@mozilla.org/alerts-service;1" in Components.classes);}
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/ee0713fbfb1a1ccfabf56679636637de9a1e3dbf/pref-mailnews.js/clean/mail/components/prefwindow/content/pref-mailnews.js