You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brandon Miller.

ASSISTANT: How can I help you?

USER: Due to some emergency work at my home town, I need to change my existing reservation that I made earlier to go for holiday trip. Can you help me out?

ASSISTANT: Wait a minute.

USER: Sure.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you for your response.