You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Steven Harris here.

ASSISTANT: How can I assist you?

USER: Can you change my existing reservation?

ASSISTANT: Sure, I will assist you.

USER: Thank you.

ASSISTANT: Can you please give me a moment to check the ticket status?

USER: Sure, take your time.

ASSISTANT: Sorry to tell you that, there is no reservation found on your name in our database to change.

USER: It's ok, thanks for your response.

ASSISTANT: Thank you for reaching us.