You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Sure, can you provide me your name please?

USER: Angela Parker.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Angela Parker. I regret to inform that there is no reservation by your name.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you.