You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Elizabeth King.

ASSISTANT: How can I assist you today?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for your valuable time. There is no reservation found on your name Elizabeth King.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you for reaching us.