You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Gregory King.

ASSISTANT: How may I lend a hand to?

USER: I need to change my existing reservation, can you please help me?

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

USER: Thank you for your kind response.

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

USER: That's ok, thank you for the information.

ASSISTANT: Thank you very much for contacting our agency.