diff --git a/functions.lua b/functions.lua
index 4521912..133846b 100644
--- a/functions.lua
+++ b/functions.lua
@@ -1484,6 +1484,31 @@ local function get_fs_talkdialog(player, n_id, d_id)
 			"a conversation is started.]")
             end
 
+	    -- chat option: Mute/Unmute NPC
+            h = h + 1
+            local obj = yl_speak_up.speak_to[pname].obj
+	    -- some precautions - someone else might have eliminated the NPC in the meantime
+	    local luaentity = nil
+	    if(obj) then
+                luaentity = obj:get_luaentity()
+            end
+	    if(luaentity and luaentity.yl_speak_up.talk) then
+                table.insert(formspec, "button[0.5," .. h .. ";53.8,0.9;mute_npc;]")
+                table.insert(formspec, "tooltip[mute_npc;The NPC will no longer show his dialogs "..
+			"when he is right-clicked. This is useful while you edit the NPC and don't "..
+			"want players to see unfinished entries and/or quests.]")
+                table.insert(formspec, "label[0.7,"..(h+0.45)..";Stop talking to other players while "..
+			"I give you new orders.]")
+            elseif(luaentity) then
+		-- unmute the NPC
+                table.insert(formspec, "button[0.5," .. h .. ";53.8,0.9;un_mute_npc;]")
+                table.insert(formspec, "tooltip[un_mute_npc;The NPC will show his dialogs to other "..
+			"players when he is right-clicked. This is the normal mode of operation. Choose "..
+			"this when you are finished editing.]")
+                table.insert(formspec, "label[0.7,"..(h+0.45)..";Talk to anyone who wants to talk to "..
+			"you.]")
+            end
+
             -- chat option: "That was all. I'm finished with giving you new orders. Remember them!"
             h = h + 1
             table.insert(formspec, "button_exit[0.5," .. h .. ";53.8,0.9;button_end_edit_mode;]")
@@ -3079,6 +3104,8 @@ function yl_speak_up.talk(self, clicker)
     end
 
     if not self.yl_speak_up or not self.yl_speak_up.talk or self.yl_speak_up.talk~=true then
+
+        -- TODO: allow to enter edit mode; show a small formspec that this npc is busy
         return
     end