You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: This side Mark Nelson.

ASSISTANT: How may I lend a hand to?

USER: I would like to cancel my recent reservation because my trip dates are postponed, can you help me?

ASSISTANT: Sure, I am here to help you for this. Let me check you reservation status in our records.

USER: Sure, take your own time.

ASSISTANT: Sorry for inconvenience, no reservation is found with your criteria.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you very much for contacting our agency.