You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you aid me to change my reservation due to emergency?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can you please share your name to check your reservation status?

USER: David Lewis here.

ASSISTANT: Ok, please give me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: Thank you for the help.

ASSISTANT: Thank you for choosing us.