You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

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

ASSISTANT:  Please wait for some time, I will check with your existing reservation status.

USER: Sure.

ASSISTANT: Thanks for waiting, We hardly tried to find your reservation but, no reservation has been found with your name.

USER: It's ok, thank you for the response.

ASSISTANT: Thanks for approaching us.