You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am planning to change my reservation, can you help me in that?

ASSISTANT: Sure, I will assist you with that. May I know your name for further process?

USER: I am Melissa Hill.

ASSISTANT: Ok, please hold on a moment.

USER: Ok.

ASSISTANT: There is no previous reservation available under your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.