You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you help me change my existing reservation which was made on the name of Gary Perez?

ASSISTANT: Sure, just a moment I will check the reservation list.

USER: Ok.

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

USER: That's ok, thank you for the information.

ASSISTANT: Thanks for approaching us.