You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: This is Emily Hall.

ASSISTANT: How may I lend a hand to?

USER: I want to change my existing reservation. Can you please help me in that?

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

USER: Ok.

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

USER: Ok, no problem.

ASSISTANT: Thank you very much for approaching our agency.

USER: Thank you.

ASSISTANT: You are welcome.