You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I lend a hand to?

USER: I am Brandon Nelson, want to alter my recent reservation due to some emergency. Please help me out with that.

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

USER: Thank you and sure, take your time.

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

USER: It's ok, thank you for your help.

ASSISTANT: Thank you very much for contacting our agency.