You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: As my exam got postponed, I want to change my existing reservation. Can you help me out?

ASSISTANT: Sure, I am at your service to help you. Can you please provide your name?

USER: Sure, my name is Emily Anderson.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Sorry Emily, no reservation found under your name.

USER: That's ok, thank you.

ASSISTANT: It's my pleasure.