You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Please help me to change my existing reservation as my trip got postponed due to bad weather conditions.

ASSISTANT: Sure, may I know your name?

USER: I am Joshua Harris.

ASSISTANT: Wait a minute.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found on your name.

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

ASSISTANT: Thank you for reaching us.