You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: As my exam got postponed, can you help me to change my existing reservation?

ASSISTANT: Sure, can I have your good name please?

USER: Sure, my name is Debra Carter.

ASSISTANT: There is no reservation found under your name to do modifications in tat.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.