You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, could you please help me with your name?

USER: Donald Baker here.

ASSISTANT: Wait a minute.

USER: Ok.

ASSISTANT: Sorry, there was no reservation found on your name.

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.