You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me in changing my existing reservation, as my exam got postponed. Please help me in changing?

ASSISTANT: Sure, please provide me your name.

USER: I am Samantha Nelson.

ASSISTANT: There is no reservation found under your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.