You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Andrew Martinez.

ASSISTANT: How may I help you?

USER: Can you help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes further.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.