You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Stephen Parker.

ASSISTANT: How may I help you?

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

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

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

USER: No issues, thank you for your information.

ASSISTANT: Thank you for reaching us.