You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I need to change my reservation as my plan to go for trekking got postponed. Can you help me?

ASSISTANT: Sure, please share me your good name.

USER: I am Dorothy Walker.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: That's fine, thanks for checking.

ASSISTANT: Thank you for reaching us.