You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jeffrey Lewis.

ASSISTANT: How may I help you?

USER: Due to sudden work, I want to change my reservation. Can you please help me with it?

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

USER: Ok.

ASSISTANT: Sorry to inform, no reservation is found with your criteria.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you very much for contacting our agency.