You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kathleen smith.

ASSISTANT: How can I assist you today?

USER: Can you change my existing reservation?

ASSISTANT: Sure, please wait for few minutes.

USER: Sure.

ASSISTANT: Thank you for your time. There is no existing reservation found on your name.

USER: Ok, No problem. Thank you.

ASSISTANT: Thank you for reaching us.