You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I provide assistance to you?

USER: I am Elizabeth Adams. Due to some health issue, I need to change my existing reservation. Can you help me in doing that?

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

USER: Sure.

ASSISTANT: Thank you for waiting, sorry to say that there were no reservation found on given name.

USER: Ok, thanks for your response.

ASSISTANT: Thank you for opting us, have a good day.