You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation, as my exams got postponed suddenly. Can you please help me with this?

ASSISTANT: Sure, I will help you. Can you please tell me your name?

USER: I am Alexander Turner.

ASSISTANT: Turner, there is no reservation with your name to change further.

USER: That's fine. Thank you for your time.

ASSISTANT: Thank you for approaching us.