added function yl_speak_up.sort_keys

functions.lua

@@ -1986,6 +1986,17 @@ yl_speak_up.get_sorted_options = function(options, sort_by)
 end
 
 
+-- simple sort of keys of a table
+yl_speak_up.sort_keys = function(t)
+	local keys = {}
+	for k, v in pairs(t) do
+		table.insert(keys, k)
+	end
+	table.sort(keys)
+	return keys
+end
+
+
 -- helper function for formspec "yl_speak_up:talk" *and* formspec "yl_speak_up:edit_option_dialog"
 -- when a parameter was changed in edit mode;
 -- this is called when the player is in edit_mode (editing the NPC);