You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am David Turner. Owning to an emergency, I would like to change my recent reservation. Could you please help me with this?

ASSISTANT: Sure, I am here to help.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry David Turner, there is no reservation found on your name.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you, hope to serve you better next time.