#73551, fix js warnings. r=hwaara, sr=bienvenu

mailnews/base/resources/content/msgMail3PaneWindow.js

@@ -203,7 +203,6 @@ function HandleDeleteOrMoveMsgCompleted(folder)
         // as the last index we had selected, the outliner isn't generating a new
         // selectionChanged notification for the outliner view. So we aren't loading the 
         // next message. to fix this, force the selection changed update.
-        var outlinerView = gDBView.QueryInterface(Components.interfaces.nsIOutlinerView);
         if (outlinerView)
           outlinerView.selectionChanged();
         EnsureRowInThreadOutlinerIsVisible(gNextMessageViewIndexAfterDelete); 
@@ -218,7 +217,6 @@ function HandleDeleteOrMoveMsgCompleted(folder)
   }
 }
 
-
 function IsCurrentLoadedFolder(folder)
 {
 	var msgfolder = folder.QueryInterface(Components.interfaces.nsIMsgFolder);

mailnews/base/resources/content/msgViewNavigation.js

@@ -95,7 +95,7 @@ function CrossFolderNavigation (type, supportsFolderPane )
   if (type != nsMsgNavigationType.nextUnreadMessage) 
   {
       // only do cross folder navigation for "next unread message"
-      return nsnull;
+      return null;
   }
 
   var nextMode = pref.GetIntPref("mailnews.nav_crosses_folders");
@@ -104,7 +104,7 @@ function CrossFolderNavigation (type, supportsFolderPane )
   // 2: "next" does nothing when there are no unread messages
 
   // not crossing folders, don't find next
-  if (nextMode == 2) return;
+  if (nextMode == 2) return null;
 
   var originalFolderURI = gDBView.msgFolder.URI;
   var nextFolderURI = null;