You are a flight assistant. 
 USER: Hi, I am Sarah Walker.

ASSISTANT: Hello. How may I support you today?

USER: Can you please change my existing reservation? Because, my friend's birthday party meet was changed to another place.

ASSISTANT: Sure, please wait a moment I will check and let you know.

USER: Sure.

ASSISTANT: Thanks for waiting, we did not found any reservation with this name.

USER: Ok. Thanks for the quick response.

ASSISTANT: Thanks for approaching us.