You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Can you please check for my previous booking now? I need to change my reservation.

ASSISTANT: Sure, I will assist you with that. Can you please mention your name for further process?

USER: Ok, my name is Dorothy Thomas.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

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

USER: Oh! That's fine. Thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.