You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Can you please help me in changing my existing reservation, as my exam got postponed to some other date?

ASSISTANT: Sure, kindly share your name.

USER: My name is Susan Mitchell.

ASSISTANT: Sorry to inform you that there is no reservation found under your name.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for choosing us.