Update bot-builder-nodejs-send-suggested-actions.md (#43)

Author: szul

articles/nodejs/bot-builder-nodejs-send-suggested-actions.md

@@ -30,6 +30,8 @@ This code example shows how to send a message that presents three suggested acti
 
 When the user taps one of the suggested actions, the bot will receive a message from the user that contains the `value` of the corresponding action.
 
+Be aware that the `imBack` method will post the `value` to the chat window of the channel you are using. If this is not the desired effect, you can use the `postBack` method, which will still post the selection back to your bot, but will not display the selection in the chat window. Some channels do not support `postBack`, however, and in those instances the method will behave like `imBack`.
+
 ## Additional resources
 
 * [Preview features with the Channel Inspector][inspector]
@@ -45,4 +47,4 @@ When the user taps one of the suggested actions, the bot will receive a message
 
 [inspector]: ../portal-channel-inspector.md
 
-[channelInspector]: https://docs.botframework.com/en-us/channel-inspector/channels/Skype/
+[channelInspector]: https://docs.botframework.com/en-us/channel-inspector/channels/Skype/