diff --git a/doc/img/setting-dialog.png b/doc/img/setting-dialog.png
index 2338935..baee7fd 100644
--- a/doc/img/setting-dialog.png
+++ b/doc/img/setting-dialog.png
Binary files differ
diff --git a/doc/index.rst b/doc/index.rst
index 6515de7..cd824b2 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -22,10 +22,13 @@
 .. image:: https://raw.github.com/bruinfish/ChronoChat-V2/master/doc/img/chronochat-1.png
 
 You should see **Setting** button at the bottom of the panel. 
-You can change your nick name there.
+You can change your identity and setting there.
 
 .. image:: https://raw.github.com/bruinfish/ChronoChat-V2/master/doc/img/setting-dialog.png
 
+The default setting is derived from the key and certificate you installed in step 0. 
+
+
 The left part of the panel is your contact list. 
 One must be one of your contacts if she/he wants to have a chat with you.
 Right now, it is empty, so let's add some contacts.